CESTRlCIONTIDiE. 
291 
P. 3155. Remains of a large head, exhibiting fragments of car¬ 
tilage, shagreen, and several teeth. Enniskillen Coll. 
P. 2146. An imperfect laterally compressed head, exhibiting teeth, 
shagreen, and the bases of three cephalic spines. The 
outlines of none of the cartilages can be discerned, but 
the left pterygo-quadrate is pressed slightly upwards, thus 
exposing the dentition of the right side, as shown, of the 
natural size, in PI. XV. fig. 1. The lateral prominences of 
the anterior teeth are scarcely evident, and thus suggestive 
of A. nobilis ; but the coarseness of the coronal markings 
and the form of the principal teeth point rather to 
A . anningice , with which the specimen is here provision¬ 
ally associated. The teeth of series n. to vi. are readily 
recognizable; and two teeth in front and one behind 
appear to be respectively referable to series i. and vn. 
The last-named tooth measures 0-011 in length, and is 
notably broad, with blunt extremities. In series ii. and 
in. the teeth are elevated to an obtuse point, with the 
longitudinal division-line of the coronal ornament forming 
a slight crest; and they measure respectively about 0 - 015 
and 0*02 in length. The teeth of the succeeding series 
are more flattened; those of no. iv. are broadest near 
the anterior extremity, measuring 0-023; those of no. v. 
(0*025 in length) are narrow in front and relatively broad 
in the posterior half, where each is almost divided into 
two by a transverse suture. In series vi. the teeth taper 
only slightly at each extremity, though most behind, and 
these attain a length of about 0-017. The shagreen is 
similar to that already described upon the head of Hybodus 
delabechei (p. 260, PI. VIII.), the largest tubercles being 
upon the frontal region, and the smallest behind; but the 
latter, so far as preserved, do not exhibit any fusion into 
groups of three. Egerton Coll. 
P. 2735. Fragment of a head, exhibiting a cephalic spine and 
numerous teeth. The cephalic spine, of which the pro¬ 
jecting portion is almost perfect, is very similar to that of 
Hybodus. The teeth are characteristic of the species, 
and those situated anteriorly have distinct lateral pro¬ 
minences. Enniskillen Coll. 
P. 2145. Fragment apparently of the upper jaw showing minute 
comparatively blunt shagreen-granules and some of the 
principal teeth. The crown of one of the larger teeth is 
v 2 
