Modifications of primitive astogenetic patterns were central to the origin of bifoliate Peronopora. Outgroup comparison with Prasopora indicates that fundamental events in the former's origin included vertical growth of basal lamina skeleton to form the median lamina and heterochronic modifications of early and later-stage astogeny. Heterochronic modifications of early astogeny included acceleration of budding rates in the ancestrular disc, disc enlargement, and reduction of the basal expansion. Later-stage heterochronic modifications included reduction of zooecial length and width of “endozonal” growth and parallel orientation of cystiphragms about maculae. Also important were “2-D” budding in longitudinal ranges and a unique mode of secondary frond formation. Paedomorphosis resulted in constraints on zoarial form, autozooecial morphology, cystiphragm patterning, and increased colonial integration. Coordination of early and later-stage astogenetic events suggests developmental integration linked to median lamina formation. Heterochronic modifications are inferred to have been products of spatial competition in early astogeny and competitive avoidance and resource exploitation in later astogeny. Restricted biogeographic distribution and characteristics of the ancestrula suggest that the larvae of bifoliate Peronopora were nonplanktotrophic.

A shared derived suite of characters including the median lamina unite the bifoliate Peronopora clade. Results of cladistic analyses indicate that bifoliate Peronopora comprise a cohesive, statistically significant clade. Character analysis, phylogenetic results, and the restricted biogeographic distribution of bifoliate species support the hypothesis of a monophyletic bifoliate Peronopora clade of generic rank. The generic concept of Peronopora is revised and limited to bifoliate species.

Of all the morphologic characters used in favositid taxonomy, corallite size has most frequently been given more weight than others because of its relative ease of measurement and because it has been generally believed to be less variable. This study evaluates the reliability of corallite size as a criterion by a statistical treatment of several populations of favositids in the Upper Silurian West Point Reef Complex in Gaspé, Québec. Calculation of corallite cross-sectional area was made feasible by computer-based image analysis which provides a quick and accurate measure of size. The present study shows that the mean of the largest 10 percent corallite areas in mature parts of colonies with a minimum sample size of 100 corallites per cross section is the best approximation available of mean adult corallite size.

It is suggested that intraspecific variability of corallite size is often too large for this character to be used in practice, probably due to phenotypic plasticity. The same may be true of most other morphologic characters. In some cases, however, one or two characters remain invariate within a species and can be used diagnostically. The same characters may be extremely variable in other species.

The Richmondian (Upper Ordovician) strata in the Central Basin of Tennessee yield an abundant and diverse fauna of brachiopods. The section consists in ascending and conformable order of the “Arnheim” and Fernvale Formations.

The following species are described: Austinella kankakensis (McChesney), Diceromyonia tersa Wang, Glyptorthis insculpta maquoketensis Ladd, Hebertella occidentalis (Hall), Onniella meeki (Miller), Paucicrura quadrata (Wang), Pionodema alberstadti n. sp., Plaesiomys bellistriatus Wang, P. proavita (Winchell and Schuchert), Platystrophia acutilirata (Conrad), P. ponderosa Foerste, Rafinesquina sp., Retrorsirostra carleyi (Hall), Strophomena planumbona (Hall), Tetraphalerella neglecta (James), Thaerodonta recedens (Sardeson), and Zygospira modesta (Hall).

Faunal comparisons confirm correlations with the Cape Limestone of southeastern Missouri, the Maquoketa Formation of Iowa, the upper part of the Viola Formation of Oklahoma, the Aleman and Cutter Formations in West Texas, and the standard Richmond section. The fauna in Tennessee connects the provincial Richmond in the Ohio Valley with the western faunas.

Glyptospira is a small, highly ornamented, turriteliform gastropod found in the Lower Permian of the southwestern United States. Two species, Glyptospira cristulata Chronic and G. arelela Plas, have been previously described from the Kaibab Formation, Arizona, and the Bird Spring Group, Arrow Canyon Range, Nevada, respectively. The genus is most diverse in the Wolfcampian Hueco Formation of West Texas and southern New Mexico and the Colina Limestone of southeastern Arizona. This contribution describes four new species of Glyptospira from the southwestern United States: two bicarinate forms, G. huecoensis and G. turrita, and two tricarinate forms, G. tricostata and G. cingulata.

A phylogenetic analysis of all known species of Glyptospira was performed using qualitative characters for which transformation series could be established and two quantitative characters for which transformation series could not be established. The phylogenetic results provided the best available hypothesis of the evolutionary history of the genus.

Despite numerous distributional studies of foraminifera in modern shallow-water carbonate environments, information loss and taphonomic bias in the transition from life to death assemblages of foraminifera in these environments have not previously been examined in detail. Surface sediment and vegetation samples were collected along six nearshore traverses and one traverse across the back reef lagoon off Key Largo, Florida. Living foraminifera are found in abundance on algae and the marine angiosperm, Thalassia testudinum, while foraminifera in sediment assemblages are represented primarily by empty tests. Q-mode cluster analysis of living assemblages on Thalassia delineates inshore (depth 0.4–2.7 m) and offshore (3.0–9.0 m) back reef biofacies. Calcareous imperforate (suborder Miliolina) species thrive in quiet waters of the inshore biofacies, in which biotic interactions appear to be the prime factor in determining small-scale species distributions of living foraminifera. Fragile species are most susceptible to test destruction, and, therefore, sediment assemblages are dominated by more robust forms (e.g., Archaias angulatus, Valvulina oviedoiana, thick-walled species of Quinqueloculina).

Water turbulence primarily determines species composition of living populations of the offshore biofacies. These assemblages are dominated by the calcareous perforate (suborder Rotaliina) species Planorbulina acervalis and Rosalina bahamaensis. These species resist transport by encrusting Thalassia blades and having a test which fits flush with grass blades, respectively. However, sediment assemblages of the offshore biofacies are also dominated by typical inshore, robust species (Archaias angulatus, thick-walled miliolids). Thus, inshore and offshore biofacies are not readily differentiated by Q-mode cluster analysis of sediment assemblages. Robust species are wide ranging and often abundant in sediment because of differential preservation and time-averaging of sediment assemblages. The resultant taphonomic bias may interfere with paleoecologic interpretations concerning intensity of water energy and distance from shore.

A new strophalosiid, Megalosia chuluensis n. gen. and sp., from the Nisal Member, Senja Formation, in the Manang district north of Mt. Annapurna, north-central Nepal, is of early Dorashamian or Changhsingian (Late Permian) age. Wyndhamia circularis Chang, from slightly older faunas of south Tibet, might be congeneric.

Significant new occurrences of Devonian articulate brachiopods retaining color patterns including Stringocephalus burtini Defrance from the Givetian of southern England with both concentric and radial bands, an undetermined stringocephalid brachiopod with concentric bands from the Givetian of the western Brooks Range, Alaska, Beachia cf. B. thunii (Clarke) from the mid-Early Devonian Oriskany Sandstone of Schoharie, New York, with a prominent pair of radial color bands, and Athyris vittata Hall from the early Givetian Ferron Point Formation of Michigan with numerous radial color bands are illustrated. The presence of preserved color patterns is documented for the first time in members of the family Stringocephalidae King and in the family Athyrididae McCoy.

Four species belonging in Tudiclidae and one in Melongenidae have been confused with perissityids. The new genus Rapopsis is proposed for a tudiclid species, R. joseana n. sp. of early Maastrichtian age. Three other tudiclid species may belong in the Tethyan genus Pyropsis, P. fantozzii n. sp. of early to middle Paleocene age, P. striata (Stanton, 1896) of later Paleocene age, and ?P. gabbi (Stanton, 1896) probably of early to middle Paleocene age. The melongenid genus Protobusycon, represented by P. judithae n. sp. of late Paleocene age, has not previously been recognized in eastern Pacific faunas.

Concepts of the family Hyolithidae Nicholson fide Fisher and the genera Hyolithes Eichwald and Orthotheca Novak have been expanded through time to encompass a variety of morphologically dissimilar shells. The Hyolithidae is here considered to include only those hyolithid species which have a rounded (convex) dorsum; slopes on the dorsum are inflated, and the venter may be flat or slightly inflated. Hyolithes encompasses species which possess a low dorsum and a prominent longitudinal sulcus along each edge of the dorsum; the ligula is short and the apertural rim is flared. The emended concept of Orthotheca includes only those species of orthothecid hyoliths which have a subtriangular transverse outline and longitudinal lirae covering the shell on both dorsum and venter.

Eighteen species of Hyolithes and one species of Orthotheca from the Appalachian region and Western Interior were reexamined in light of more modern taxonomic concepts and standards of quality for type material. Reexamination of type specimens of H. similis Walcott from the Lower Cambrian of Newfoundland, H. whitei Resser from the Lower Cambrian of Nevada, H. billingsi Walcott from the Lower Cambrian of Nevada, H. gallatinensis Resser from the Upper Cambrian of Wyoming, and H. partitus Resser from the Middle Cambrian of Alabama indicates that none of these species represents Hyolithes. Hyolithes similis is here included under the new genus Similotheca, in the new family Similothecidae. Hyolithes whitei is designated as the type species of the new genus Nevadotheca, to which H. billingsi may also belong. Hyolithes gallatinensis is referred to Burithes Missarzhevsky with question, and H. partitus may represent Joachimilites Marek. The type or types of H. attenuatus Walcott, H. cecrops Walcott, H. comptus Howell, H. cowanensis Resser, H. curticei Resser, H. idahoensis Resser, H. prolixus Resser, H. resseri Howell, H. shaleri Walcott, H. terranovicus Walcott, and H. wanneri Resser and Howell lack shells and/or other taxonomically important features such as a complete aperture, rendering the diagnoses of these species incomplete. Their names should only be used for the type specimens until better preserved topotypes become available for study. Morphology of the types of H.? corrugatus Walcott and “Orthotheca” sola Resser does not support placement in the Hyolitha; the affinities of these species are uncertain.

Stromatoporoids are the principal framebuilding organisms in the patch reef that is part of the reservoir of the Normandville field. The reef is 10 m thick and 1.5 km2 in area and demonstrates that stromatoporoids retained their ability to build reefal edifices into Famennian time despite the biotic crisis at the close of Frasnian time. The fauna is dominated by labechiids but includes three non-labechiid species. The most abundant species is Stylostroma sinense (Dong) but Labechia palliseri Stearn is also common. Both these species are highly variable and are described in terms of multiple phases that occur in a single skeleton. The other species described are Clathrostroma cf. C. jukkense Yavorsky, Gerronostroma sp. (a columnar species), and Stromatopora sp. The fauna belongs in Famennian/Strunian assemblage 2 as defined by Stearn et al. (1988).

Even though ammonites are not very abundant in Patagonia, a large number of specimens were collected by geologists from the Empresa Nacional del Petroleo (ENAP), Chile, during the course of several years of field work in the Magallanes Basin. This study describes the ammonite family Kossmaticeratidae present in that collection, which is a typical element of most southern hemisphere Late Cretaceous assemblages. The species described include: Kossmaticeras (Kossmaticeras?) fasciculatum n. sp., K. (Karapadites) constrictus n. sp., K. (Natalites) cecioni n. sp., K. (Natalites) hauthali (Paulcke), K. (Natalites) sp., Neograhamites kiliani Spath, N. taylori Spath, Gunnarites elegans n. sp., G. bhavaniformis (Kilian and Reboul), Grossouvrites gemmatus (Huppe), and Maorites densicostatus (Kilian and Reboul).

The stratigraphic information on this fauna indicates that it is distributed in four assemblages. The oldest (assemblage A), possibly late Santonian to early Campanian in age, includes the species Kossmaticeras (Kossmaticeras?) fasciculatum, Neograhamites taylori, and possibly N. kiliani. This is followed by assemblage B (possibly middle to late Campanian), with K. (Karapadites) constrictus, K. (Karapadites) centinelaense (Blasco, Nullo, and Proserpio), K. (Natalites) hauthali, K. (Natalites) cecioni, Neograhamites morenoi Riccardi, N. taylori, N. kiliani, K. (Natalites) sp., Gunnarites elegans, G. bhavaniformis, and possibly Pseudokossmaticeras paulckei Collignon. The third assemblage (C), possibly late Campanian to early Maastrichtian in age, contains G. elegans, G. bhavaniformis, Grossouvrites gemmatus, and K. (Natalites) hauthali. The youngest assemblage (D) is possibly late Maastrichtian in age and is composed of the species Maorites densicostatus and Grossouvrites gemmatus.

Two Upper Triassic sphinctozoan sponges of the family Sebargasiidae were recovered from silicified residues collected in Hells Canyon, Oregon. These sponges are Amblysiphonella cf. A. steinmanni (Haas), known from the Tethys region, and Colospongia whaleni n. sp., an endemic species. The latter sponge was placed in the superfamily Porata by Seilacher (1962). The presence of well-preserved cribrate plates in this sponge, in addition to pores of the chamber walls, is a unique condition never before reported in any porate sphinctozoans. Aporate counterparts known primarily from the Triassic Alps have similar cribrate plates but lack the pores in the chamber walls. The sponges from Hells Canyon are associated with abundant bivalves and corals of marked Tethyan affinities and come from a displaced terrane known as the Wallowa Terrane. It was a tropical island arc, suspected to have paleogeographic relationships with Wrangellia; however, these sponges have not yet been found in any other Cordilleran terrane.

Pulvinites lawrencei n. sp. is described from the upper Paleocene (Landenian Stage) Paspotansa Member of the Aquia Formation in Stafford County, Virginia. This is the first report of a member of the pteriacean family Pulvinitidae in the Tertiary on either side of the Atlantic, the only other post-Mesozoic records of Pulvinites being in the Paleocene of California and the present-day Pacific off southeast Australia. The stratigraphic setting and co-occurring molluscan assemblage of the new species indicate shallow-shelf, open-marine conditions with near normal salinities.

Two new species of worm tubes referable to the genus Onuphionella occur in Lower Cambrian strata in eastern California and western Nevada. Onuphionella durhami n. sp. is found in the Campito Formation (in pre-trilobite strata, in the Fallotaspis and, possibly, the Nevadella Zones) and O. claytonensis n. sp. occurs in the Middle Member of the Poleta Formation (Nevadella Zone). The unusual tubes are armored with an imbricated coat of mica flakes, reminiscent of the modern genus Owenia. The lowest occurrence of Onuphionella in western North America corresponds closely with the lowest occurrence of the genus in the Baltic region, indicating that correlations between the two regions are not greatly in error.

The early tabulate coral Lamottia heroensis has been identified from the Ion Member of the Decorah Formation (Upper Ordovician) in northeast Iowa. This extends the stratigraphic range of this species upward from Lower Chazyan to Kirkfieldian, and extends the geographic range from the Vermont-New York border area to include the north-central Midcontinent. Thin section and SEM studies strongly support the contention that the longitudinal pattern of alternating light and dark bands observed in corallite walls reflects a primary structural grain rather than a secondary diagenetic feature.

Eleven basic constructional designs are defined among the Crinoidea. Calyx designs are defined primarily by shape, geometry of plates at the base of the calyx, tegmen shape, fixed calyx plates, number of arms, and nature of radial facets. These calyx designs include the following: multiplated bowls, multiplated bicones, conical mosaics, urns, cylinders, cones, ellipsoids, hands, bowls, bilateral recumbents, and fists. Most crinoid subclasses and orders contain crinoids with several of these designs. This significant convergence and parallelism in calyx design indicates that the morphological evolution of crinoids has been substantially constrained by constructional and fabricational limitations.

Four trilobite species are present in the Gilmore City Limestone (Kinderhookian–Osagean) of Humbolt County, Iowa. The most common trilobite taxa, Perexigupyge hodgesi n. gen. and sp. and Perexigupyge gerki n. gen. and sp., make up the greatest percentage of the trilobite population. Two other species are known from fragmentary cranidia and are assigned to the genera Richterella and Proetides. Prior to the description of these forms, the only trilobite previously described or illustrated from the Gilmore City Limestone was a cranidium of Proetides insignis (Winchell) from the type area.

The Gilmore City Limestone in Humbolt County, Iowa, represents deposits associated with an oölitic sand-shoal environment, including washover-lobe and back-shoal deposits. Morphologic attributes exhibited by the Gilmore City Limestone trilobites, such as low relief and vaulting to the exoskeleton and subdued surface ornamentation, may have been adaptations that enabled them to inhabit current-swept shoal environments. Conversely, coarsely tuberculate forms may have used the tubercules as a mimic of the surrounding coarse-grained sediment or to strengthen the exoskeleton.

The composition of Permian members of the superfamily Subulitacea is considered, and 12 new species of Subulitacea are described from the silicified fauna of the Permian System of West Texas and New Mexico. Other elements of the gastropod fauna were previously described by Yochelson (1956a, 1960) and Batten (1958).

The new genus Ischnoptygma is established for subulitaceans possessing a plate-like columellar fold, and includes the new species Ischnoptygma archibaldi and I. valentinei. The genus is placed within the new family Ischnoptygmidae. New species of Subulitidae are Ceraunocochlis deformis, C. elongata, C. kidderi, C. trekensis, Strobeus girtyi, Soleniscus diminutus, S. variabilis, Cylindritopsis hamiltonae, and C. spheroides. The status of the genus Labridens is questioned, but provisionally retained. The assignment of the family Meekospiridae to the Subulitacea is questioned, and a single new species, Meekospira mimiae, is described.

Four species of Emilites are now known; these are E. incertus (Böse), E. plummeri Ruzhencev, E. brownwoodi n. sp., and E. bennisoni n. sp. Representatives of this genus may occur as early as Middle Pennsylvanian in North America to as late as Early Permian in the Soviet Union. All described taxa are from North America except E. plummeri, which is from the Soviet Union. Because Emilites is extremely rare in upper Paleozoic ammonoid assemblages, generic and species level phylogenetic relationships are poorly understood. Emilites is not considered to be a good generic-level zone indicator due to its relatively long time range and its rarity.

The evolution of primitive calceocrinids with four arm-bearing rays, here termed cremacrinids, has been examined for 13 species of Cremacrinus, Paracremacrinus, and Anulocrinus using numerical cladistics. The lineage was reconstructed from a Wagner tree of a Manhattan distance matrix. The characters were polarized by outgroup comparison. The Calceocrinidae originated from the Homocrinidae by development of the hinge, recumbent stem, loss of the BC interray basal and the C ray arm, and reorganization of the dorsal cup plates. The main evolutionary trends within cremacrinids consist of differentiation of the B and E ray arms from those of the lateral rays, increase or decrease in the number of branches and size of all arms, reduction of the B ray arm relative to those of the A and D rays, acquistion of additional main axils in the lateral rays, fusion of the infer- and superradials in the B and C rays, development of elongate brachials, and changes in adult body size.

Relatively complete growth sequences are known for six species of cremacrinids and these are analyzed with allometric equations for the dorsal cup, hinge, and arms. The relationships between ontogeny and phylogeny for the links in the evolutionary sequence and the number of examples of each are listed in order of decreasing frequency and importance: 1) unclassified divergences (for example, changes in the number of branches in the E ray and the formation of elongate brachials), 12 examples; 2) 10 cases of paedomorphosis; 3) no significant differences between ancestors and descendants, seven instances; 4) five links where the dorsal cup plates are rearranged; and 5) a single change by recapitulation. Some phyletic links are characterized by several patterns whereas others only exhibit one or two kinds of transitions.