TAXOCRINIDAE 439 



( ?) Onychocrinus polydactylus (M'Coy) 

 Plate LXIV, figs, n-14 



Taxocrinus polydactylus M'Coy, Syn. Carb. Fossils Ireland, 1844, p. 178, pi. 26, fig. 7 (Cladocrinus on 

 Plate).— Roemer, Verh. Nat. Hist. Ver. Preuss. Rheinland, VIII, 1851, p. 366 (Separate, p. 10). — 

 Morris, Cat. British Fossils, 2d Ed., 1854, p. 90. — Meek and Worthen, Proc. Acad. Nat. Sci. Phila- 

 delphia, IX, 1865, p. 140. — Quenstedt, Petrefaktenkunde Deutschlands, IV, 1876, p. 504, pi. 107, 



fig- 143. 



Cyathocrinus polydactylus, Roemer in Bronn, Lethaea Geognostica, I, pt. 2, 1852-54, p. 237. 



Onychocrinus polydactylus, Wachsmuth and Springer, Revision Palaeocrinoidea, I, 1879, p. 55. 



Poteriocrinus ? egertoni Phillips, Geology Yorkshire, II, 1836, p. 205, pi. 3, fig. 39. — Quenstedt, Petrefak- 

 tenkunde Deutschlands, IV, 1876, p. 503, pi. 107, fig. 140. 



Isocrinus egertoni Phillips, Palaeozoic Fossils Cornwall, 1841, p. 30. 



Cladocrinites egertoni, Austin and Austin, Ann. and Mag. Nat. Hist., XI, 1843, p. 197. 



Taxocrinus egertoni, Morris, Cat. British Fossils, 1843, p. 59. 



A large-sized species, with very elongate crown. Rays long and slender, 

 tapering slowly, the rami being nearly as heavy as the rays below them. 

 Ramules thick, branching at intervals of two to five brachials at the inside of 

 the dichotom. Calyx narrow, with few interbrachials. IBB covered by column. 

 BB visible as fairly large pentagons. IBr 6 or more, narrowing slightly 

 upward. Anal structure unknown. Column tapering rapidly from the calyx 

 for a short distance, beyond which the thin columnals alternate with slightly 

 projecting nodals. Height of maximum crown, estimated, 70 mm. 



This is one of the two known representatives of the Onychocrinus type from British 

 rocks, or others outside of America. Unfortunately we do not know enough of its structure 

 to determine with certainty its generic relations, but it presumably has the weak anal side 

 consistent with its greatly extended and divergent rays, and therefore will belong somewhere 

 near the company in which I have placed it. M'Coy's figure in the Carboniferous Fossils 

 of Ireland, which I have copied (PI. LXIV, fig. 11), is a restoration, composed from three 

 fragments which I have also figured, two of which undoubtedly belonged to the same 

 specimen. I have placed them in their probable relative position, with the missing parts 

 drawn in outline (fig. 12). We are materially assisted in this by the other fragment 

 (fig. 13), which shows that there were at least six primibrachs, as the fifth one preserved in 

 it is not axillary. These specimens are located in the Science and Art Museum, Dublin, and 

 I am much indebted to Dr. R. F. Scharff, the Curator, for photographs and accurate casts 

 from which to illustrate them. 



There is no doubt that Phillips's Poteriocrinus egertoni, which is from the same region 

 of the Irish Carboniferous, belongs to this species. Unfortunately the type cannot be found ; 

 it was in the collection of Sir Philip Egerton, afterward acquired by the British Museum, 

 and Dr. Bather assures me that it has been an object of long and fruitless search by him. 

 Although Phillips says the species was abundant at Florence Court, Enniskillen, there is no 

 specimen in the great collection of Lord Enniskellen, now also in the British Museum, 

 which can be referred to it, nor have I been able to locate any other specimens among all 

 the Irish collections. I have copied Phillips's figure of P. egertoni (fig. 14), which confirms 

 the evidence of M'Coy's fragment as to the great number of brachials below the first bifur- 

 cation. The figure is palpably incorrect in the short, sharp-pointed arms, which doubtless 

 had that appearance on account of being partly buried in the matrix, and having none of 

 the ramules exposed ; it represents a young specimen as compared with M'Coy's, which is 

 drawn natural size. ■ 



