﻿50 CHlMiEKOIDEI. 



above the right mandibular tooth rests the small incisor- 

 like presymphysial tooth (ps.) r which is shown in side view 

 and transverse section, of three times the natural size, in 

 figs. 4 a, 4 b. This tooth is much worn at its rounded 

 functional extremity, and appears in transverse section 

 (fig. 4 b) as if bent upon its mesial longitudinal line, which 

 is in the form of a rounded ridge externally and a deep 

 concavity internally ; the tubular dentine does not cover 

 the whole of the inner face, but forms a band occupying 

 the greater part of the width of the concavity. The pair 

 of anterior upper teeth (v.) is displayed from the oral 

 aspect, each consisting of a broad triangular hinder portion, 

 and a narrow quadrangular anterior portion, the latter 

 crossed by few transverse ridges of laminated dentine. A 

 fragment of one of the hinder upper teeth (jol.) is too 

 imperfect for description,, Some of the thorn-shaped der- 

 mal tubercles, upon expanded bases, evidently from the 

 rostral spine, occur higher upon the slab (t.) : and the 

 basal half of the spine itself is shown from the dorsal 

 aspect immediately adjoining. This spine expands at its 

 base more gradually than that of Squaloraja, which it 

 otherwise resembles in form : and there are traces of a 

 very fine superficial granular ornament. EnnisJcillen Coll. 



P. 1158. Fragmentary remains of head and dorsal fin-spine. Por- 

 tions of the hinder pair of upper teeth are shown from the 

 attached surface, and further posteriorly there is a trian- 

 gular dermal plate, exposed from the outer aspect. This 

 plate is raised to a somewhat excentric acuminate apex, 

 and is covered with tuberculations arranged more or less 

 in radiating lines ; it is shown, of twice the natural size, 

 in PI. III. fig. 4. The dorsal spine is much crushed and 

 abraded, but exhibits a few downwardly pointing posterior 

 denticles distally, while a long series of upwardly directed 

 denticles is preserved on the anterior border. Egerton Coll. 



P. 3099. Left mandibular tooth, exposed from the oral aspect, and 

 shown, of the natural size, in PL III. fig. 3. The sym- 

 physis (fig. 3, a) is narrow and shows the characteristic 

 bevelling (s), much extended, probably for the accommo- 

 dation of the mediau incisor-like tooth ; while the oral 

 surface is undulating, with one oblique median ridge and 

 a somewhat raised post- oral border, neither parallel with 

 the symphysial border, but much less nearly vertical. The 



