Published online by Cambridge University Press: 01 May 2009
Some years ago the British Museum acquired from Dr. William Clark a collection of the remarkable Arthrodira found by him in the Upper Devonian shales of Ohio. In this material there are several specimens which were described as new before being brought to Europe, but concerning which there has been more or less doubt among students of the Arthrodira. Hitherto, however, it has been quite impossible to dispel this doubt since the material necessary to a comparative study of the forms in question is to be found only in America. Last year I enjoyed the privilege of going over this material in the British Museum, thanks to the courtesies extended to me by Dr. Arthur Smith Woodward, F.R.S., the Keeper of Geology, and as I had just come from a study of the American forms I was in a position to resolve these doubtful cases. The results of this study are presented in the following pages.
page 124 note 1 “On a new Plaeoderm, Brontichthys Clarki, from the Cleveland Shale”: Amer. Geologist, vol. xiv, pp. 379–80, pl. xii.Google Scholar “On a new gigantic Plaeoderm from Ohio”: Third Ann. Rep. Ohio State Acad. Sci., 1895, pp. 8–9.Google Scholar
page 125 note 1 Mem. N.Y. Acad. Sci., vol. ii, p. 101, 1910.Google Scholar
page 126 note 1 Mem. N.Y. Acad. Sci., vol. ii, pl. vi, fig. 36.
page 126 note 2 Ibid., pl. vi, fig. 33, MO.
page 126 note 3 Ibid., fig. 38.
page 128 note 1 In Newberry's Paleozoic Fishes of North America (pl. ix, fig. 2), this element is figured in outer view, but not quite correctly. It represents a second cusp which in reality does not pertain to the specimen, but is an adherent superimposed fragment. The line from the point of the tooth to the posterolateral termination of the element is gently convex, but quite smooth.