CHIltfiEBIDJE. 
55 
Genus GANODUS ? Agassiz (emend. A. S. W.) 1 . 
[Poiss. Foss. toI. 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 Ischyodus. 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. CMmcera (Gcmodus ) 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. Gcmodus oiveni, Sir P. Egerton, Quart. Journ. Geol. Soc. vol. iii. 
p. 352. 
1890. Gcmodus oiveni , A. S. Woodward, Proc. Geol. Assoc, vol. xi. 
p. 303. 
(P) 1890. Ganodus sp., A. S. Woodward, ibid. pi. iii. fig. 4. 
Type. Theoretically associated mandibular and palatine teeth ; 
British Museum. 
Mandibular tooth with a gently wavy oral margin and a relatively 
long post-oral margin much less vertically inclined than the sym- 
ph} T sial 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. 
