CENTRISCIM. 
377 
Family CENTRISCIDzE. 
Trunk laterally compressed, and irregularly oblong or deepened ; 
snout much produced into a tube, and small toothless mouth 
terminal. Gills pectinated ; opercular apparatus complete. Some 
anterior vertebrae usually elongated, those of the abdominal region 
and some anterior caudals with large transverse processes. Pelvic 
fins without spine but with 5 or 6 divided rays; an enlarged spine 
and usually other small spines in front of the dorsal tin ; anal fin 
Without anterior spine, opposed to the soft dorsal ; caudal fin 
distinct. Skin with a partial bony armour and also with small 
scales. 
These are small marine fishes, very widely distributed. 
Synopsis of Genera. 
Caudal region relatively large ; few dorsal spines, 
the second excessively enlarged; pelvic fins 
considerably behind pectorals ; bony plates 
dorsaUy and ventrally and flanks covered 
with small scales Centriscus (Recent). 
Caudal region relatively large ; pelvic fins partly 
beneath pectorals ; bony plates dorsallv, not 
ventrally, but flanks covered with small 
scales Hhampliosus (p. 377). 
Caudal region relatively very small ; pelvic fins 
reduced, considerably behind pectorals ; dorsal 
and ventral bony dermal armour extensive, 
but no scales Amphisile (p. 378). 
Isolated spines from the Lower Pliocene of Orciano, Tuscany, are 
'■'scribed to Centriscus under the name of C. toni by It. Lawley, 
^ uov i Studi Pesei, etc., Colline Toscane (1876), p- 79. 
Genus RHAMPHOSUS, Agassiz. 
[Poiss. Foss. vol. iv. 1S44, p. 270.] 
Trunk only moderately deepened ; caudal region relatively large, 
with about *14 vertebra. Pelvic fins well-developed and far 
foi wards, partly beneath the pectorals ; caudal fin rounded. Bony 
Piates dorsally in abdominal region to support the large spine, but 
110 ventral armour ; small rough scales covering flanks. 
Rhamphosus aculeattis (Blainville). 
I '96. Uranoscopus rostrum^ G. S. Aolta, Ittiolit. Veronese, p. xxii. 
pi. v. fig. 4. 
1796. Centriscus , G. S. Volta, ibid. pi. lxxv. fig. 1 (errors) . 
