GEKEES.— POMADASIS. 41 



16. Gerres brevimanus, GUnth., 18G4. 



Gerres brevimanus, Jord. & Everm. t. c. p. 1377. 



Hah. Brackish-water lakes at Chiapam, Guatemala {Salvin); Pacific Coast of Panama. 



17. Gerres mexicanus, Steind., 1863. 



Gerres mexicanus, Jord. fe Everm. t. c. p. 1380. 

 Hah. Rio Teapa, Mexico. 



Fam. 10. POMADASID-ffi. 



A large and important group of marine fislies, chietij' 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., 1803. 



Pristipoma, Giinth. Cat. Fish. i. 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 

 pra?orbital ; jaws equal anteriorly or the lower somewhat the shorter ; bauds of small villiform teeth in 

 the jaws ; palate toothless. A median pit or groove behind the symphysis of the lower jaw. Prae- 

 operculum serrated ; serra; on lower limb not directed forwards. A single dorsal, with X-XIV 10- 1 8 

 rays, with a more or leas 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 asynDuetrical, pointed ; veiitrals below 

 or a little behind the base of the pectorals, with 1 5 rays ; a scaly process at the base of s])ine of each 

 ventral fin. 



jlah. Tropical and subtropical seas, a few species entering rivers. 



Synopsis of the Species found in the Bivers of Mexico and Central America. 



Scales above the lateral line in series parallel to the lateral line. Dorsal XI-XIII 11-17. Anal 111 6-i) *. 



I. A series of small scales on the membrane behind each branched ray of the dorsal fin. 



Second anal spine not longer than third 1. leuciscus. 



Second anal spine longer than third . 2. macracantJins. 



* Other species which present these features and which may prove to be fluviatile are P. nilidus, P. a.rillans, 

 and P. panamensis from the Pacific Coast, and P. corvinceformis from the Atlantic. P. panamensis is related to 

 P. crocro, the others to P. leuciscKS. The genus C'onoJon, with a species on each coast, is rery close to 

 Pomadasis of the type of P. bi-anicl-i. It is distinguished by the enlarged outer teeth and the strongly serrated 

 prseopercle, with antrorse serras below the angle. 



BIOL. CENTR.-AMER., Pisces, February 1907. G 



