BLOCHITDA BLENXIIDiE. 
595 
of the upper series being slightly smaller than those of 
the lower series. Purchased , 1846. 
*• 2089. Caudal region and other fragments of a small specimen. 
There are traces of scutes on the cheek. Egerton Coll. 
Family BLENNIID2E. 
Elongated fishes with stout caudal pedicle ; snout not produced. 
Most of the abdominal vertebrae with downwardly directed transverse 
processes bearing the small ribs. Dorsal fin occupying nearly the 
whole of the back, often subdivided ; anal fin also much extended ; 
caudal fin rounded or tapering. Scales small or absent, and no bony 
scutes. 
Marine fishes living at the bottom near almost all coasts, and a 
few freshwater species. Scarcely known among fossils, but repre- 
sented by at least one extinct genus allied to Cristiceps, and perhaps 
by another ( Oncolepis ) of doubtful affinities. 
Genus PTERYGOCEPHALUS, Agassi*. 
[Poiss. Eoss. vol. iv. 1839, p. 190.] 
Head short and orbit very large ; mouth small, with conical teeth. 
\ ertebrse about 10 in the abdominal, 14 in the caudal region. Dorsal 
fin very deep, the foremost large spine displaced forwards above the 
head but the fin otherwise continuous. Squamation well developed 
and continuous, each scale with a longitudinal keel, and the keels 
forming regular lines along the trunk. 
An Eocene genus, erroneously identified with Cristiceps 1 by 
J- Miiller, Is cues Jahrb. 1853, p. 123. 
Pterygocephalus paradoxus, Agassiz. 
1796. Lahrus malapterus, G. S. Volta, Ittiolit. Veronese, p. ccxxviii. 
pi. lv. fig. 3 (errore ) . 
1818. Lahrus malapterus, II. D. de Blainville, Nouv. Diet. d’Hist. Nat. 
vol. xxvii. p. 351. 
1835. Pteryyocephalus paradoxus, L. Agassiz, Neues Jahrb. p. 295 
(name only). 
1839. Pterygocephalus paradoxus , L. Agassiz, Poiss. Foss. vol. iv. 
p. 191, pi. xxxii. figs. 5, 6. 
1876. Cristiceps paradoxus, F. Bassani, Atti Soc. Veneto-Trent. Sci. 
Nat. vol. iii. p. 178. 
1 Cuvier & Valenciennes, Hist. Nat. Poiss. vol. xi. (1836), p. 402. 
2q2 
