Zoarium unilaminate, adherent.

Zoæcia convex, quite separate, very small, average length .35 to .38 mm. and width .2 mm.; numerous radiating imperforate lines are faintly perceptible on some of them in a suitable light, and were doubtless present on all; they are hardly ‘furrows’, resembling rather superficial cuts; apertures very slightly heel-shaped.

Oæcia abundant, relatively large, globose with a strongly concave free edge.

The receipt of a grant from the Trustees of the Percy Sladen Fund in 1911 made a return to the Balearic Islands possible in the latter part of the same year. Majorca was visited for the third time while a search for Pleistocene ossiferous remains was undertaken for the first time in Menorca and Ibiza, from which no Pleistocene mammalian remains had previously been recorded. No success attended the search in Ibiza. The deposits discovered in Menorca yielded remains of Myotragus balearicus, those of a gigantic land tortoise, and of a large Eliomys, which proves to be a hitherto undescribed species.

The majority of the numerous papers that have already been published on the petrology of Kalgoorlie have dealt with the subject only in a more or less general way. Few investigators have hitherto devoted their energies to the study of one portion of the field, and even Larcombe, whose main thesis seems to have been the study of the Golden Mile, has chosen an area in which owing to the magnitude and depth of the lode formations, and the consequent chemical and thermodynamic alterations, definite clues as to the original rock types could hardly be expeoted to remain, since there can be no doubt that in petrology, as in stratigraphy, much light can occasionally be thrown on the most difficult portions of a field by the study of the outlying portion. It has therefore been with considerable interest that the investigation of the North End has been begun.

Edrioaster bigsbyi was first made known by E. Billings in June, 1854, and was referred by him, though with some doubt, to Agelacrinites. He gave no specific name, but regarded his fossils as identical with the specimen found by Bigsby at the Chaudière Falls and described by G. B. Sowerby in 1825 (see Study III), and as “almost identical with A. Buchianus” of Forbes, 1848 (see Study II). This series of papers by Billings contains several important observations and reasonings not reproduced in those later more official publications of his to which alone subsequent writers seem to have gone for information. From the original account it is clear that the specimens there called Agelacrinites were the same as those which Billings described in 1857, under the name Cyclaster bigsbyi. The misapprehension that caused Billings to apply to his new species the trivial name bigsbyi has already been dealt with in Study III; the species has nothing to do with the specimen found by Bigsby. In 1858 Billings discovered and pointed out his error, and, realizing further that the generic name Cyclaster had been taken by G. Cotteau for a sea-urchin a few months before his own use of it, he redescribed the species under the name Edrioaster bigsbyi. The independence of the genus itself was denied in 1860 by E. J. Chapman, who referred the species back to Agelacrinites. The textbook writers, however, generally accepted Edrioaster, and no change was made in either name or description until Professor Haeckel in 1896 thought fit to alter the name to Edriocystis.