60 
CHIMJEKOIDEI. 
Ischyodus colei (Agassiz). 
[Plate I. fig. 14.] 
1843. Chimcera ( Ganodus ) colei, L. Agassiz {ex Buckland, MS.), Poiss. 
Foss. yoI. iii. p. 346, pi. xl. figs. 8-10. 
1843. Ischyodus coin, Sir P. Egerton, Proc. Geol. Soc. vol. iv. p. 156. 
1847. Ganodus colei, Sir P. Egerton, Quart. Journ. Geol. Soc. vol. iii. 
p. 352. 
1890. Ischyodus colei, Woodward & Sherborn, Cat. Brit. Foss. Verte- 
brata, p. 105. 
Type. Theoretically associated mandibular and palatine teeth; 
British Museum. 
(?) Mandibular tooth with a gently wavy oral margin and a 
relatively long post-oral margin nearly parallel to the symphysial. 
Palatine tooth with all the tritors of small size, the posterior inner 
being larger than the other three taken together, and the median 
tritor the smallest of all. 
The type specimen of the mandibular tooth not being sufficiently 
perfect for definition, the palatine tooth may be regarded as the 
type of the species. 
Form. Log. Bathonian (Stonesfield Slate): Oxfordshire. 
P. 1134 a. Bight mandibular tooth, outer aspect, much abraded, 
figured by Agassiz, tom. cit. pi. xl. fig. 8; Stonesfield. 
Egerton Coll. 
P. 480. Left palatine tooth, oral aspect, figured by Agassiz, ibid. 
fig. 9, and re-figured in PI. I. fig. 14; Stonesfield. 
Eaerton Coll. 
P. 1134. Bight palatine tooth, superior aspect; Stonesfield. 
Egerton Coll. 
P. 3101-2. Four palatine teeth, one showing the superior aspect, 
the others the oral aspect; Stonesfield. 
Enniskillen Coll. 
Ischyodus emarginatus, Egerton. 
1843. Chimcera {Ischyodus) emarginata, Sir P. Egerton, Proc. Geol. Soc. 
yoI. iv. pp. 154, 156. 
1843. Chimcera {Ischyodon) tessoni, L. Agassiz, Poiss. Foss. vol. iii. 
p. 342, pi. xl. fig. 19. [Mandibular tooth; British Museum.] 
Type. Left mandibular tooth ; British Museum. 
This species is only provisionally retained distinct from I. egertoni , 
the difference of proportions not sufficing to justify its separation. 
