﻿CH1.U.K1UD.K. 63 



surface below and behind the apex of the anterior outer tritor. 

 '?) Palatine tooth with the posterior inner tritor of large size, and the 

 median tritor not extending further forwards than this ; outer tritor 

 much elongated and extending far forwards. 



Form. Sf Loc. Kimmeridge Clay : Boulogne, N. France. 



32416. Left mandibular tooth, probably referred to by Sauvage, 

 op. cit. p. 74. Purchased, 1857. 



32767. More imperfect large specimen, of the right side. 



Purchased, 1857. 



32768. Right palatine tooth. Purchased, 1857. 



Ischyodus beaumonti, Egerton. 



1843. Chimcera {Ischyodus) beaumonti, Sir P. Egerton, Proc. Geol. 



Soc. vol. iv. pp. 155, 156. 

 1843. Chimcera (Ischyodon) beaumontii, L. Agassiz, Poiss. Foss. vol. iii. 



p. 346. 

 1847. Ischyodus, Sir P. Egerton, Quart. Journ. Geol. Soc. vol. iii. 



p. 351, pi. xiii. fig. 1. 



1866. Ischyodus beaumontii, E. T. Hamy, Bull. Soc. Geol. France, [2] 

 vol. xxiii. p. 655, woodc. fig. 1. 



1867. Ischyodus beaumontii, H. E. Sauvage, Catal. Poiss. Form. 

 Second. Boulonnais (Mem. Soc. Acad. Boulogne, vol. ii.), p. 83, 

 pi. iv. figs. 4, 5. 



(?) 1867. Ischyodus rigauxi, H. E. Sauvage, ibid. p. 76, pi. iv. figs. 14, 



15. [Mandibular tooth ; Boulogne Museum.] 

 1890. Ischyodus beaumonti, Woodward & Sherborn, Cat. Brit. Foss. 



Vertebrata, p. 105. 



Type. Eight palatine tooth. 



(?) Mandibular tooth with a very gently wavy oral margin, a 

 short post-oral margin nearly parallel to the symphysial, and the 

 beak more or less produced and acute ; beak-tritor small, elongated 

 antero-posteriorly, with one or two minute tritors immediately 

 within ; both outer tritors present, though small ; median tritor 

 very large and broad, occupying the greater portion of the oral as- 

 pect and nearer the post-oral than the symphysial margin. Pala- 

 tine tooth with the posterior inner tritor of large size, and the median 

 tritor not extending so far forwards as this ; outer tritor somewhat 

 elongated. (?) Vomerine tooth relatively deep, with a series of small 

 tritors. 



The mandibular tooth assigned to this species is described by 

 Sauvage under the name of /. rigaucci. 



Form. Sf Loc. Eammeridge Clay : N. France and Dorsetshire. 



