﻿84 CHIMiKROIDEI. 



droit," and regarded as the type of a Miocene species of 

 Ischyodus — Chimcera (Ischyodon) helvetica ; Molasse, 

 Olten, Soleure, Switzerland. The specimen is referred to 

 Edaphodon by F. J. Pictet, Paleontologie, ed. 2, vol. ii. 

 (1854), p. 233. Egerton Coll. 



The following dorsal fin-spines from the English Chalk may also 

 be assigned to Edaphodon : — 



39068. Slender spine, somewhat broken, 0*183 in length ; Maid- 

 stone. Bowerbank Coll. 



36749. Greater portion of similar spine ; Hailing, Kent. 



Purchased, 1862. 



49731. Similar spine, wanting extremities ; Lewes. Capron Coll. 



P. 1153. fragments of slender spine ; Kent. Egerton Coll. 



46401. Portion of stouter spine; Lower Chalk, Warminster, Wilt- 

 shire. Cunnington Coll. 



43390. Portion of large spine ; Burham, Kent. Purchased, 1872. 



P. 6255. Fragments of large spine, provisionally assigned by Agassiz 

 to Edaphodon [" Chimosra "] mantelli (Poiss. Foss. vol. iii. 

 1843, p. 64, pi. x.6. fig. 17); Lewes. Mantell Coll. 



P. 3097. Basal portion of similar spine ; Lewes. EnnisTcillen Coll. 



49025-6. Portions of two large spines ; locality uncertain. 



Mrs. Smith's Coll. 



A dorsal fin-spine, probably of Edaphodon, has also been described 

 from the Cretaceous of Central Eussia by S. Mkitin, Mem. Comite 

 Geol. vol. v. no. 2 (1882), p. 42, pi. iv. fig. 16. Another fin-spine, 

 possibly of this genus, from the Cretaceous Greensand of New 

 Jersey, is named Sphagepoea aciculata, E. D. Cope, Proc. Amer. 

 Phil. Soc. vol. xi. (1869), p. 241. 



The species mentioned below have also been determined upon the 

 evidence of detached teeth, and, by a misunderstanding of the 

 generic characters, the majority of the American forms have hitherto 

 been ascribed to Ischyodus. Most of the type specimens of the 

 latter are in the collection of Prof. E. D. Cope, Philadelphia, where 

 the present writer has had the privilege of examining them ; and 

 many of the specific distinctions cited in the diagnoses would be 

 regarded as varietal in Britaia. Unless otherwise stated, the type 

 specimen is a mandibular toc f h : — 



