CniROCENTRrDiB. CTE.NOTHRISSID.K 
119 
49763. Imperfect jaws ; Southeram. Capron Coll. 
49764-65. Detached left dentary and a small skull, both frag- 
mentary ; Lower Chalk, Amberley Pit, Arundel. 
Capron Coll. 
P. 3849. Fragmentary jaws ; Arundel. Enniskillen Coll. 
49767-68. Two small fragmentary heads; Lower Chalk, Dorking, 
Surrey. Capron Coll. 
25925. Imperfect left mandibular ramus and another fragmentary 
mandible, the first figured by Dixon, op. cit., as the type 
of a distinct species, Tomognathus leiodus ; Washington, 
Sussex. Dixon Coll. 
The following specimens are not specifically determined : — 
P. 6460 a. Remains of small head and opercular apparatus, remark- 
able for the very large size of the anterior teeth, which 
are especially tumid at the base, incurved and not fluted 
even in the apical portion ; Chalk, S.E. England. The 
nutritive foramina in tho dentary are large, while the 
operculum and suboperculum are covered with small pits 
which have a raised border. Deckles Coll. 
47242. Fragmentary remains of a large head, exhibiting a non- 
fluted anterior mandibular tooth ; Chalk Marl, Dover. 
Gardner Coll. 
37325. Fragment of small head ; Chalk Marl, Dover. 
Purchased , 1863. 
Family CTENOTHRISSID/E. 
Supraoccipital bone prominent, but parietals partly meeting in 
the middle line ; squamosal reduced and apparently fused with 
pterotic ; snout not produced ; check-plates reduced. Premaxilla 
small and maxilla relatively largo and loose, both these bones 
entering the upper border of the mouth ; two supramaxillarics ; 
teeth acuminate, but feeble. Opercular apparatus complete, but 
few branchiostegal rays and no gular plate. Vertebral centra well 
ossified, none with transverse processes ; ribs nearly encircling the 
abdominal cavity. Fin-fulcra absent, and simplo rays in front of 
dorsal fin slightly spaced ; post-temporal bones in contact with 
postero-lateral angles of cranium ; post-clavicular plate overlapped 
by tho clavicle ; pelvic fins relatively large and advanced far for- 
wards. Scales thin and deeply imbricating. 
