STR0MATBID2B. 
419 
Family STROMATEIDiE. 
Snout not produced into an elongated rostrum ; premaxillae 
sometimes protractile ; dentition feeble. Vertebrae between 28 and 
111 number ; the posterior abdominal centra with downwardly - 
er 't transverse processes. Pelvic fins, when present, thoracic, with 
one spine and five articulated rays ; dorsal and anal fins much 
extended, each with few crowded anterior spines gradually increasing 
>n length to foremost articulated ray, which is longest. Scales very 
sma H and regular, usually extending over the cheek and bases of 
Ae median fins ; lateral lino 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. 
Ihe three extinct genera recorded below are only provisionally 
placed in this family. 
Genus OMOSOMA, Costa. 
[Mem. It. Accad. Sci. Napoli, vol. ii. 1857, p. 106.] 
Cleft of mouth small, only slightly oblique, and jaws with very 
minute teeth. Vertebra: about 12 in the abdominal, 16 to 18 in 
n e caudal region. Postclavicle much elongated and slender, 
reaching ventral border ; pelvic fins slightly behind the pectorals ; 
Oorsal and anal fins acuminate in front, with very few, moderately 
8 t °ut, anterior spines, gradually lengthening and closely pressed 
together; caudal fin deeply forked. Scales small, smooth, and 
eycloid, apparently longer than deep, extending over the opercular 
apparatus, head, and base of dorsal and anal fins. 
Omosoma sahel-almae) Costa. 
18o7. Omosoma sach-el alvue, O. G. Costa, Mem. K. Accad. Sci. Napoli, 
vol. ii. p . 106, pi. i. fig. 1. 
188 7. Omosoma sah-eUalmce , J. W. Davis, Trans. Roy. Dublin Soc. [2] 
vol. iii. p. 643, pi. xxv. fig. 5. 
1887. Imogaster auratus, J. W. Davis, ibid. p. 541, pi. xxviii. fig. 3 
(errors). 
Type. Imperfect fish ; Geological Museum, University of Naples. 
The type species, attaining a length of about 0-1. Length of head 
Wlt h opercular apparatus equal to maximum depth of trunk and 
ono third total length of fish to fork of tail. Dorsal fin with about 
2e 2 
