396 
AOTINOPTERYGII. 
The blunt anterior end of the rostrum, well shown in 
side-view (fig. 1 a), exhibits a slight mesial vertical ridge. 
There are some traces of closed sutures in the cranial roof, 
but the fragments are too imperfect for satisfactory deter¬ 
mination. Leeds Coll. 
P. 6914. Imperfect rostrum about half as large as the type, asso¬ 
ciated with the tooth-bearing border of the dentary bone; 
near Peterborough. Only the base of the left vomerine 
tooth is preserved ;■ and instead of two enlarged marginal 
teeth anteriorly, there is but one. A transverse section 
of one of the large teeth of the dentary is prepared for 
microscopical examination, and exhibits the complex 
structure noted in Ann. Mag. Xat. Hist. [6] vol. xiii. 
(1894), p. 511. Leeds Coll. 
P. 6915. Abraded large right splenial with remains of anterior end 
of dentary, probably of this species ; near Peterborough. 
Leeds Coll. 
P. 6833. Fragments of skull and pectoral fin probably of this 
species : near Peterborough. Leeds Coll. 
Hypsocormus tenuirostris, A. S. Woodward. 
[Plate XI. figs. 2-6.] 
1889. Hypsocormus tenuirostris, A. S. Woodward, Geol. Mag. [3] 
vol. vi. p. 451. 
Type. Remains of skull; British Museum. 
An imperfectly known species about as large as H. macroclon. 
Snout acutely pointed and produced so that its length in advance of 
the large vomerine teeth somewhat exceeds its breadth at their 
insertion; external surface finely granulated; the large vomerine 
teeth directed almost vertically. 
Form. <$f Log. Oxfordian : Huntingdonshire. 
P. 6916. The type specimen, comprising rostrum, right maxilla and 
premaxilla, portion of left dentary, and other associated 
fragments ; Oxford Clay, near Peterborough. The ros¬ 
trum (PI. XI. figs. 2, 2 a) is comparatively narrow and 
acutel}' pointed, and there is a considerable extension in 
advance of the vomerine area (fig. 2, v.a.). The whole of 
the external surface is ornamented with fine tubercles. 
The two vomers seem to be fused into one bone, and the 
greater part of the large tooth of the right sido is pre¬ 
served, while the socket only of that on the left is exhibited. 
