ELOPIDiE. 
47 
P. 1749. Type specimen, shown of two thirds the natural size from 
the left lateral and inferior aspects in PI. III. figs. 1, 1 a. 
The general proportions of the cranium are indicated, but 
the bones are much fractured and some may be distin¬ 
guished more readily in the next specimen. The otic 
region is well ossified, and the sphenotic (or postfrontal, 
jpt.f.) enters the anterior end of the facctte for the hyo- 
mandibular. The latter element Qim.) is much constricted 
and bent forwards mesially, while the slender process (p.) 
for the support of the operculum (op.) arises from the 
lower end of its upper half. This bone seems to be a 
little displaced backwards by crushing, the remains of the 
quadrate (qu-) and probably of the symj)lectic (sy.) being 
well forwards. The fragments of the metapterygoid 
(mpt.) and ectopterygoid (ecpt.) do not suffice for descrip¬ 
tion. The snout is incomplete, but the greater part of 
' the mandible is shown on each side. The articulo-angular 
element (ag.) is relatively large, with very low articular 
facette; the depth of the coronoid region seems to have 
equalled one quarter the total length of the ramus, and 
the dentary (d.) gradually tapers forwards. The teeth in 
the anterior half of the mandible, so far as preserved, are 
much larger than those in its posterior half, which are 
best seen on the right side. All are smooth, acutely 
pointed, and inclined a little backwards. Part of a com¬ 
paratively deep suboperculum (s.op.) is preserved; the 
uppermost branchiostegal ray (hr.) is shown to be rather 
large, but the others, not less than 14 in number, are 
only imperfectly indicated; the gular plate (gu.) wants 
merely its anterior end. Egerton Coll. 
P. 640. Another imperfect head, displaying the hinder part of the 
cranial roof (PI. III. fig. 2), remains of the characteristic 
cheek-plates, and part of the opercular apparatus. This 
specimen is labelled EurygnaiJius cavifrons by Agassiz, and 
was intended by him to be the type of the species. The 
robust supraoccipital (s.occ.), with a posterior keel, is well 
shown at the back of the cranial roof, articulating with 
the large epiotic (epo.) on either side. The frontals (fr.) 
are shown to extend close to this occipital border; they 
are bounded on either side in their hinder portion by 
membrane-bones which seem to be identifiable as squa¬ 
mosal (sq.), but the parietals cannot be recognised with 
