STKOMATEID^. 
419 
Family STROMATEID^. 
Snout not produced into an elongated rostrum; premaxillse 
sometimes protractile ; dentition feeble. Yertebraj between 28 and 
40 in number; the posterior abdominal centra with downwardly- 
bent transverse processes. Pelvie fins, when present, Ihoraeic, with 
one spine and five articulated rays; dorsal and anal fins much 
extended, each with few crowded anterior spines gradually increasing 
in length to foremost articulated ray, which is longest. Scales very 
small and regular, usually extending over the cheek and bases of 
the median fins ; lateral line conspicuous. In the existing forms:— 
air-bladder usually absent; oesophagus pierced and armed with 
numerous horny, barbed gill-rakers. 
Pelagic and littoral fishes very widely distributed in tropical and 
temperate regions. 
The three extinct genera recorded below are only provisionally 
placed in this family. 
Genus OMOSOMA, Costa. 
[Mem. R. x4ccad. Sci. Yapoli, vol. ii. 1857, p. 106.] 
Cleft of mouth small, only slightly oblique, and jaws with very 
minute teeth. Vertebrae about 12 in the abdominal, 16 to 18 in 
the caudal region. Postclavicle much elongated and slender, 
reaching ventral border ; pelvie fins slightly behind the pectorals ; 
dorsal and anal fins acuminate in front, with very few, moderately 
stout, anterior spines, gradually lengthening and closely pressed 
together; caudal fin deeply forked. Scales small, smooth, and 
cycloid, apparently longer than deep, extending over the opercular 
apparatus, head, and base of dorsal and anal fins. 
Omosoma sahel-almae, Costa. 
1857. Omosoma sach-el almce, 0. G. Costa, Mem. R. Accad. Sci. Napoli, 
vol. ii. p. 106, pi. i. fig. 1. 
1887. Omosoma sali-eUalmce, J. W. Davis, Traus. Roy. Dublin Soc. [2] 
vol. iii. p. 543, pi. xxv. fig. 5. 
1887. Imogaster auratus^ J. W. Davis, ihid. p. 541, pi. xxviii. fig. 3 
(errore). 
Type. Imperfect fish ; Geological Museum, University of Naples. 
The type speeies, attaining a length of about OT. Length of head 
with opercular apparatus equal to maximum depth of trunk and 
one third total length of fish to fork of tail. Dorsal fin with about 
2 E 2 
