GERRES.—POMADASIS. 4] 
16. Gerres brevimanus, Giinth., 1864. 
Gerres brevimanus, Jord. & Everm. t. c. p. 1877. 
Hab. Brackish-water lakes at Chiapam, Guatemala (Salvin); Pacific Coast of Panama. 
17. Gerres mexicanus, Steind., 1863. 
Gerres mexicanus, Jord. & Everm. t. c. p. 1380. 
Ilab. Rio Teapa, Mexico. 
Fam. 10. POMADASIDA. 
A large and important group of marine fishes, chiefly from tropical seas. The 
species of the widely distributed genus Pomadasis are numerous, but only a few ascend 
rivers. About thirty-five members of this genus are found on the coast of Tropical 
America, and six of these are known to enter rivers freely and must be considered 
here. 
1. POMADASIS, Lacep., 1808. 
Pristipoma, Ginth. Cat. Fish. 1. p. 286 (1859). 
Body compressed ; scales small or of moderate size, ctenoid. Lateral line complete, usually curved. Mouth 
rather small or of moderate size, protractile; entire length of upper edge of maxillary slipping under the 
preorbital; jaws equal anteriorly or the lower somewhat the shorter ; bands of small villiform teeth in 
the jaws; palate toothless. A median pit or groove behind the symphysis of the lower jaw. Pre- 
operculum serrated ; serra on lower limb not directed forwards. A single dorsal, with X—-XIV 10-18 
rays, with a more or less distinct scaly sheath at the base ; soft fin not densely covered with small scales. 
Anal with III 7-13 rays. Caudal truncate or forked. Pectoral asymmetrical, pointed ; ventrals below 
or a little behind the base of the pectorals, with 15 rays; a scaly process at the base of spine of each 
ventral fin. 
IIab. Tropical and subtropical seas, a few species entering rivers. 
Synopsis of the Species found in the Rivers of Meaico and Central America. 
Scales above the lateral line in series parallel to the lateral line. Dorsal XI-XIII 11-17. Anal III 6-9 *. 
I. A series of small scales on the membrane behind each branched ray of the dorsal fin. 
Second anal spine not longer than third . . . . 2... se + + + + Ld, leuciscus. 
Second anal spine longer than third. . 2... 1 6 ee ee te macracanthus. 
* Other species which present these features and which may prove to be fluviatile are P. nitidus, P. axillaris, 
and P. panamensis from the Pacific Coast, and P. corvineformis from the Atlantic. P. panamensis is related to 
P. crocro, the others to P. leuciscus. The genus Conodon, with a species on each coast, is very close to 
Pomadasis of the type of P. branicki. It is distinguished by the enlarged outer teeth and the strongly serrated 
preopercle, with antrorse serre below the angle. 
BIOL. CENTR.-AMER., Pisces, February 1907. G 
