PACHYCORMIDJE. 
397 
A few teeth of variable size are arranged in a single 
irregular series on the margin of the vomerine area, the 
largest being three teeth on the right side. The pre¬ 
maxilla (figs. 3, 3 a, pmx.) is triangular in form anil 
laterally compressed, with thickened alveolar border; 
and the upper margin of its inner face exhibits a long 
narrow facette (/.) for direct articulation with the cranium. 
The maxilla (figs. 3,3 a, mx.) is long and slender and gentl}* 
arched, and sends forwards a process (incomplete in this 
specimen) on the inner side of the premaxilla resting 
immediately above its thickened oral border (fig. 3 a , p.). 
Posteriorly the hone is imperfect, but there remains part 
of the rugose facette overlapped by the supramaxilla 
(fig. 3, s.rnx.). The outer face of the maxilla, as also the 
lower portion of the outer face of the premaxilla, is orna¬ 
mented with fine tuberculations like those of the rostrum ; 
and the extreme outer margin of the alveolar border bears 
very minute teeth or pointed tubercles. The teeth of the 
maxilla are comparatively small and uniform, all well¬ 
spaced ; while those of the premaxilla are much larger, 
closely arranged, and apparently largest in the middle of 
the bone. The dentary (fig. 4) is imperfect, only the 
thickened alveolar border being preserved, though this 
for the greater part of its length. The teeth are fused 
with the bone in sockets which are incomplete on the 
inner side ; they are all well spaced, largest in the middle 
of the element, and considerably exceed the maxillary 
teeth in size. Leeds Coll. 
P. 6917. Imperfect head and portions of fins of a typical fish; near 
Peterborough. The extremity of the rostrum is wanting, 
and the head is so much fractured that several interesting 
features in its osteology are exhibited. All the external 
bones are ornamented with very fine, closely-arranged 
tuberculations. The cranium is too much crushed for 
description; but a robust ossification is shown in the 
prefrontal region on the right side, and the greater part 
of the parasphenoid is also exposed. The latter element 
is considerably expanded in front and bears an elongate 
patch of minute granular teeth immediately in advance of 
the pair of foramina for the internal carotids. Among 
the remains of cheek-plates, some of the characteristic small 
circumorbitals are shown on the left side. The maxillm 
(mx.) and premaxilloe (pmx.), similar to those of the last 
