58 ACANTHOPTERYGIL. 
Snout as long as eye; maxillary extending to below anterior 4 of eye; depth of 
body 23-3 in the length; 8 guirakers on the lower part of anterior arch. 4. harengulus. 
6. Premaxillary processes } the length of head; 7 gill-rakers on the lower part of 
anterior arch. 
Depth of body 24-24 inthelength . 2... . . . ee ee ee. 5. ealiforniensis. 
Depth of body 8-32 inthelength . . . . . 1. ) ee ee ee + 6. pseudogula. 
B. Anal IL8. 7. lefroyi. 
II. Preoperculum finely serrated. 
A. Preorbital entire; no conspicuous dark longitudinal lines along the series of scales. 
1. Anal III 8. 
a. Second dorsal spine from # to as long as the head. 
Maxillary extending nearly to below middle of eye (in specimens of 220 mm.) ; 
4, scales between pectoral and ventral. . . . . © - . . . + + . 8. peruvianus. 
Maxillary extending to below anterior 4 of eye (in a specimen of 220 mm.) ; 
3 scales between pectoral and ventral. . . . . - - + - + + ~ + 9 oltthostomus. 
b. Second dorsal spine } the length ofhead . . . . . . . . . 10. aureolus. 
2, AnalII9 . . 1. ee ee ee ee ee ee ee LL. rhombeus. 
B. Preorbital finely serrated; conspicuous dark longitudinal lines along the series of scales. 
1. Pectoral extending to, or nearly to, origin of anal. 
a. Second anal spine as long as longest dorsal spine. 
a. Anal III 8. 
4 scales between lateral line and middle of dorsal fin ; 15 gill-rakers on the 
lower part of anterior arch . . 2 . - - toe ee ew wee 12. Lineatus. 
3 scales between lateral line and middle of dorsal fin; 12 gill-rakers on the 
lower part of anterior arch . 2 2. ee ee eee ee ee 18, aaillaris. 
8 AnallJI7 ... . Loe ee . . . . . 14. patao. 
b. Second anal spine #—3 as long as longest dorsal spine. ‘Anal Ill 8. 15. plumieri. 
2. Pectoral not extending. to origin of anal. Anal ITI 8. 
Second anal spine # as long as longest dorsal spine; pectoral 7-% the length 
ofhead. . . . . . Co ee ee ee ee ee ee 16. brevimanus. 
Second anal spine 2 as long as longest dorsal spine ; pectoral as long as head. 17. mexicanus. 
1. Gerres cinereus, Walbaum, 1792. 
NXystema cinereum (part.), Jord. & Everm, Bull. U.S. Nat. Mus. xlvii. 1898, p. 1872, and 1900, 
fig. 556. 
Hab. Atlantic Coasts from Florida to Brazil; freshwater ponds of Barbados. 
2. Gerres simillimus, sp.n. (Tab. VIII. fig. 2.) 
Xystema cinereum (part.), Jord. & Everm. |. c. 
Depth of body 24-24 in the length, length of head 8 to 3}. Snout as long as or longer than eye, the 
diameter of which is more than } the length of head; interorbital width 2? to 3 in the length of head. 
Maxillary extending to below anterior + of eye. Preorbital and preoperculum entire. 8 gill-rakers 
on the lower part of the anterior arch. 40-43 scales in a longitudinal series, 4 between lateral line and 
