﻿CFTTM iERTD M. 55 



Genus GANODUS, Agassiz (emend. A. S. W.) 1 . 



[Poiss. Foss. vol. iii. 1843, p. 339.] 



Syn. Leptacanthus, L. Agassiz, ibid. 1837, p. 27 (in part). 

 Psittacodon, L. Agassiz, ibid. 1843, p. 340 (in part). 



An imperfectly known genus comprising species only of small 

 size. Mandibular tooth as in Ischyodiis. Palatine tooth robust, 

 with a well-defined hard layer upon the outer aspect immediately 

 above the oral margin ; posterior border deeply notched, the sinus 

 continued forwards as a median longitudinal groove, gradually 

 becoming shallower, and separating the inner from the outer tritors ; 

 inner tritors forming a narrow longitudinal band, more or less dis- 

 continuous ; outer tritors similar, but smaller, and the two series 

 usually connected anteriorly. 



As remarked by Agassiz, the median and outer tritors of the 

 mandibular teeth are remotely placed and closely approximated ; 

 they are, however, never fused together, and the characters of the 

 palatine teeth only are sufficient to justify the separation of the 

 genus from Ischyodus. 



Ganodus oweni, Agassiz. 

 [Plate I. fig. 9.] 



1843. Chimcera (Ganodus) owenii, L. Agassiz, Poiss. Foss. vol. iii. 



p. 347, pi. xL figs. 6, 7. 

 1843. Ischyodus oiveni, Sir P. Egerton, Proc. Geol. Soc. vol. iv. p. 156. 

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



p. 352. 

 1890. Ganodus oweni, A. S. Woodward, Proc. Geol. Assoc, vol. xi. 



p. 303. 

 (?) 1890. Ganodus sp., A. S. Woodward, ibid. pi. iii. fig. 4. 



Type. Theoretically associated mandibular and palatine teeth ; 

 British Museum. 



Mandibidar tooth with a gently wavy oral margin and a relatively 

 long post-oral margin much less vertically inclined than the sym- 

 physial margin ; median tritor immediately behind and below the 

 anterior outer tritor, somewhat narrower than the space between it 

 and the symphysial margin, and notched antero-superiorly. (?) Pala- 

 tine tooth with the inner tritoral series almost continuous in its 

 posterior half, the outer series consisting of minute, well- separated 

 tritors. 



1 Sir Philip Egerton states (Quart. Journ. Geol. Soc. vol. iii. 1847, p. 350) 

 that he defined this genus in 1843. There does not appear, however, to be any- 

 published record. 



