86 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
Genus 25. OPISTHONEMA Gill. Thread-herrings. 
Characters essentially those of Sardinella, except that the last ray of the dorsal is produced in a 
long filament as in Dorosoma, Megalops, and Tarpon. Species few, American. 
32. Opisthonema og'linum (Le Sueur) . Thread Herring; Machuelo; Cailleu-Tassart; Sprat. 
Head 4.7; depth 3.2; eye 3.6; snout 3.3; maxillary 2.5; mandible 2.1; interorbital 4; D. 17 to 19; 
A. 23; pectoral 1.4; ventral 2.7; caudal 0.6; scales 50-15; scutes about 31. 
Body much compressed below, ventral outline trenchant, much more strongly arched than dorsal; 
head small; mouth small, the wide maxillary reaching about to front of pupil, the lower jaw barely 
projecting; opercle with a deep emargination at lower angle; adipose eyelid present; fins small, last 
dorsal rav greatly produced, reaching base of caudal in younger individuals, somewhat shorter in older 
ones; pectoral fitting into a shallow depression; ventral small, with an accessory scale nearly as long as 
fin; anal extremely low; caudal lobes long and slender, subequal ; scales large, cycloid, rather loosely 
attached; lateral line absent. 
Color in spirits : Bluish above, silvery below, back with interrupted brownish longitudinal stripes 
along middle of rows of scales; a dusky shoulder-spot, the young with a series of smaller spots behind, 
and black-tipped caudal lobes. 
West Indies, north to the Carolinas, occasionally to Massachusetts; common; 47 examples, 3.25 
to 9 inches, from San Juan Market, Palo Seco, Mayaguez, Guanica, Hucares, Isabel Segunda, and 
Fajardo; one from San Geronimo. 
Clapea thrissa Broussonet, Iehthyologie, fasc. I, 1782, Carolina; Jamaica; not of Osbeck, 1757. 
Megalops oglinci Le Sueur, Jour. Ac. Nat. Sci. Phila., I, 1817, 359, Newport, R. 1. 
Megalops notata Le Sueur, Jour. Ac. Nat. Sci. Phila., I, 1817, 359, Guadeloupe, 
Chatoessus signifer De Kay, N. Y. Fauna: Fishes, 264, 1842, New York. 
Chatoessus eumorphus Gosse, Nat. Sojourn in Jamaica, 290, 1851, Jamaica. 
Opisthonemus thrissa, Poey, Fauna, Puerto-Riquena, 343, 1881; Stahl, l.c.,80 and 166, 1883. 
Opisthonema oglinum, Jordan & Evermann, 1. c.,432, 1896. 
Genus 26. ILISHA Gray. 
Body much compressed, thorax and abdomen strongly serrated. Scales moderate; lower jaw 
prominent; mouth moderate with rasp-like bands of minute teeth on jaws, palatines, pterygoids, and 
tongue; none on vomer. Anal fin very long; ventrals present, small, inserted before the small dorsal; 
upper ray of pectoral strong; caudal deeply forked. 
Tropical coasts of America and Asia. Only one species known from Porto Rico. 
a. Anal rays 40 to 45; anal placed behind dorsal. 
6. Dorsal rays 19 or 20; eye 4 in head flavipinnis 
bb. Dorsal rays 15; eye 3.5 in head bleekeriana, 33 
33. Ilisha bleekeriana (Poey). Manjua; Anchoa Pelada. 
Depth 5.66 in length with caudal; eye 3.5; D. 15; A. 43; scutes 25; ventral line strongly curved. 
Mouth wide, oblique. Anal placed behind dorsal; length of anal equal to its distance from posterior 
border of eye. Scales very caducous. Silvery. 
Matanzas, Cuba; rare. Not obtained by us, but included on the authority of Poey and Stahl. 
Pellona bleekeriana Poey, Repertorio, II, 242, 1867, Matanzas, Cuba; Poey, Fauna Puerto-Riquena, 343, 1881; Stahl, 1. c. 
79 and 166, 1883. 
Ilisha bleekeriana, Jordan & Evermann, 1. c., 436, 1896. 
Family XVIII. ENGRAUUDIDtE. The Anchovies. 
Body elongate, more or less compressed, covered with thin cycloid scales. Head compressed. 
Mouth extremely large, more or less oblique, usually overlapped by a pointed, compressed, pig-like 
snout. Gape very wide, maxillary very long and slender, formed of about three pieces, extending back- 
ward far behind eye, in some species beyond head. Premaxillaries not protractile, very small, firmly 
joined to maxillaries. Teeth usually small, sometimes obsolete, usually fine and even, in a single row 
