ICIITHYOCRINIDAE 273 



Ichthyocrinus pyriformis (Phillips) 

 Plate XXXII, figs. 1-13 



Cyathocrinites pyriformis Phillips in Murchison, Silurian System, 1839, p. 672, pi. 17, fig. 6. . 



Carpocrinus pyriformis, Miiller, 1843, p. 33. 



Cyathocrinus pyriformis, Hall, Nat. Hist. New York, Pal. II, 1852, p. 196. — Quenstedt, Petrefaktenkunde 

 Deutschlands, IV, 1876, p. 502. 



Ichthyocrinus pyriformis, D'Orbigny, Prodr. Pal. Stratigraphique, I, 1849, p. 46. — Morris, Cat. Brit. Foss. 

 2nd Ed. 1854, p. 83. — M'Coy, British Palaeozoic Fossils,- 1854, P- 54- — E. Billings, Canadian Nat. 

 and Geol., I, 1856, p. 59. — Pictet, Traite Paleontologie, IV, p. 319. — Phillips in Murchison, Siluria, 

 3d Ed., 1859, P- 2 46 {Ichthyocrinus {Cyathocrinites) on plate] pi. 14, fig. 8. — Beyrich, Monatsber. 

 Akad. Wiss. Berlin, 1871, p. 45 (Transl. in Ann. and Mag. Nat. Hist., (4) VII, p. 403. — Salter, Cat. 

 Cambrian and Silurian Fossils, 1873, p. 126. — Angelin, Icon. Crin. Sueciae, 1878, p. 13, pi. 22, fig. 22 

 (not pi. 17, fig. 6 = Clidochirus) . — Wachsmuth and Springer, Revision Palaeocrinoidea, pt. I, 1879, 

 P- 35- — Quenstedt, Petrefaktenkunde, 1885, p. 947, pi. 76, fig. 1. — Bather, Ann. and Mag. Nat. Hist., 

 (6) IX, Mar.' 1892, p. 206; (piriformis) Rep. Museums Assoc, for 1891 [1892], p. 92; Treatise on 

 Zoology (Lankester) pt. 3, 1900, p. 188, fig. 108. — Springer, Jour. Geology, XIV, 1906, p. 477. 



Curious Fossil, Ellis, Philosophical Transactions, LII, 1762, p. 361, pi. 13, Fig. B. 



Encrinus, Whitehurst, An Enquiry into the Origin, State and Formation of the Earth, 1786, p. 235, pi. 7, 

 fig. 1 (after Ellis). 



Fig Pentacrinite Parkinson, Organic Remains of a Former World, 1808, pp. 258, 270, 271, 274, pi. 19, 

 fig. 2 (after Ellis). 



Cyathocrinites tuberculatus Miller (in part), Nat. Hist. Crinoidea, 1821, p. 88, fig. 2. 



Pentacrinus tuberculatus, Quenstedt, Petrefaktenkunde Deutschlands, IV, 1876, p. 193, pi. 97, fig. 7. 



Ichthyocrinus laevis, Angelin (in part) 1878, p. 13, pi. 91, figs. I7a-c (not pi. 22, figs. 20, 21= I. got- 

 landicus). 



A rather small species. Crown elongate, pyriform, with truncate base; 

 expanding gradually, with spread of calyx from RR to upper IIBr of 1 to 4; 

 height to width at that level, about i to 1.3; greatest width, about IIIBr 3 . Side 

 outline of calyx generally curving from concave below to convex; cross-section 

 subcircular; median radial ridges obscure or absent. Crown of maximum 

 specimen, 42 mm. high by 26 mm. wide at IVBr; but the average size of the 

 specimens is much less — about 22 by 18 mm. ; average width of base, 4 mm. 

 Surface ornamented with small raised granules, often confluent and forming 

 ridges or wrinkles parallel to margin of plates. 



IBB of moderate size, covered by column. BB touching column, appear- 

 ing in pentagonal outline, and usually well developed, but not large or com- 

 pletely exposed. Brachials somewhat rounded transversely, lower ones 

 averaging twice as wide as high, proportionally wider above. IIBr generally 

 4, sometimes 3 ; IIIBr, 5 to 9, with one or two more bifurcations visible. Column 

 expanding rapidly at the calyx to a diameter equal to that of the base. 



This species resembles /. laevis more closely than any other, and Hall 1 considered them 

 identical ; while Angelin 2 referred a Gotland specimen of pyriformis to the latter species. 

 The original description, though meager, throws some light upon its specific relations. 

 Phillips, whose intuitive judgment of character^ was always sagacious, was struck by the 

 essential peculiarities of the form, and while describing it under Cyathocrinus stated that it 

 ought probably to constitute a new genus ; and he called attention to the great width, general 

 equality, and lateral union of the plates as constituting easy characters — a generic definition 



1 Nat. Hist. New York, Geol. Fourth District, 1843, p. 112; idem.. Palaeontology, vol. 2, 1852, p. 196. 



2 Icon. Crin. Suec, 1878, p. 13. 



