THE FISHES OF PORTO RICO. 
209 
164. Gerres olisthostomus Goode & Bean. Mojarra; Irish Pompano; Mutton-fish. 
Head 3; depth 2.4; eye3.4; snout3.4; maxillary 2.6; mandible 1.9; interorbital 3.2; scales 6-39-11; 
D. ix, 10; A. hi, 8. Body compressed, rather long, rhomboid, more slender than in G. brasilianus 
dorsal outline in a double curve from tip of snout to origin of dorsal, strongly convex from nape to 
dorsal fin; snout conical, bluntish; mouth little oblique, large, maxillary reaching anterior edge of 
orbit; exposed portion of maxillary oblong, length 2.75 times its width; eye moderate; preorbital 
entire; preopercle weakly serrate; premaxillary groove broad, oval, covered with small, deciduous 
scales, a naked, linear, median depression. Fins moderate; first dorsal spine very short, the second 
long and moderately strong, about 2 in head, others gradually shorter; second anal spine strong, 1.6 in 
head, slightly shorter than third; caudal deeply forked, lobes longer than head; pectoral as long as 
head; ventrals shorter, 1.4 in head; least depth of caudal peduncle 1.8 in head. 
Color, silvery-olivaceous; scales with faint silvery streaks but no dark ones; fins mostly pale or 
yellowish, ventrals somewhat dusky. 
Found in the West Indies, north to southern Florida, south to Brazil. Length a foot or less. Appa- 
rently not common in Porto Rico, as the collection contains but one specimen, obtained in the San Juan 
market. This is 8.5 inches long, and differs somewhat from Florida examples, the second dorsal 
spine being shorter and the body more slender. 
Genes olisthostoma Goode & Bean, Proc. U. S. N. M. 1882, 423, Indian River, Florida. 
Gerres olisthostomus, Jordan & Evermann,!. c., 1376, 1898. 
165. Gerres brasilianus Cuvier & Valenciennes. Mojarra. 
Head 3.4; depth 2.3; eye 3.4; snout 3.25; maxillary 2.75; mandible 2; interorbital 3.3; scales 
6-36-17; D. ix, 10; A. in, 8. Body compressed, rhomboidal, back very much elevated; profile 
nearly straight from tip of snout to origin of dorsal fin, slightly concave above eyes; snout conical, 
bluntish, less acute than in G. linealus; mouth horizontal, rather large, maxillary reaching middle of 
pupil, its exposed portion oblong, about 2.75 times as long as wide; preorbital and preopercle serrate; 
eye rather large; premaxillary groove very broad, narrowed posteriorly, without scales. First dorsal 
spine very short, second very long and strong, 1.2 in head; third slightly shorter but much weaker; 
remaining dorsal spines short; dorsal rays short, about 2 in head; second anal spine very long and 
strong, 1.2 in head; third spine slender and slightly longer than second; caudal widely forked, middle 
rays about 3.5 in outer; pectoral long, 0.9 in head, reaching past vent; ventrals long, 1.15 in head; 
least depth of caudal peduncle 2.5 in head. Length a foot or less. 
F. C. B. 1900—14 
