102 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 99 



SYNGNATHUS PELAGICUS Linnaeus 



Syngnathus pelagicus Linnaeus, Systema naturae, ed. 10, p. 337, 1758. 



U.S.N.M. No. 123164, 1 specimen, 183 mm., Point Macolla, U. S. S. Niagara, 

 April 19, 1925. 



SYNGNATHUS FISTULATUS Peters 



Syngnathus fistulatus Peters, Monatsb. Akad. Wiss. Berlin, 1868, p. 456 

 (Puerto Cabello [undoubtedly Venezuela]). 



Order PERCOMORPHOIDEA 



Suborder Percesoces 



Family ATHERINIDAE: Silversides; Pescados del rey, o Pejerreres 



This family of world-wide distribution has only four species so far 

 known from Venezuelan waters. They may be distinguished by 

 means of the following key: 



la. Four glandlike depressions on dorsal surface of snout; anus far forward, 

 equidistant or nearer pelvic bases than anal fin origin; air bladder and body 

 cavity not reaching anywhere near to opposite anal fin origin; first dorsal 

 origin notably in front of anal origin; scaly sheath along base of anal fin 

 consisting of a few scales anteriorly; margins of scales wdth entire edges; 

 ascending premaxillary process a narrow spinelike projection; dorsal rays 

 IV or V — I, i, 7 or I, i, 8; anal rays I, i, 14; scales about 44. 



Adenops analis Schultz 



16. No glandUke depressions on dorsal surface of snout as in Adenops; anus just 



in front of anal origin or much closer to anal origin than to pelvic bases; 



ascending premaxillary process a wide-based triangular projection; margins 



of scales entire. 



2a, Posterior end of body cavity extending to anal origin or well past anal fin 



origin; belly rounded; no sheath of scales along anal fin base; first dorsal 



origin over or nearly over anal origin, sometimes over base of first 



branched anal ray; dorsal rays III or IV — I, i, 5 to I, i, 7; anal rays 



I, i, 14 to I, i, 19. 



3a. Scale rows from upper angle of gill opening to midbase of caudal fin 38 



to 40 Xenomelaniris brasiliensis (Quoy and Gaimard) 



ob. Scale rows 41 or 42 Xenomelaniris venezuelae (Eigenmann) 



26. Posterior end of body cavity notably not reaching anal fin origin; belly 

 compressed; anal fin base with a wide scaly sheath composed of two rows 

 of scales along its entire length; first dorsal origin over bases of fourth or 

 fifth branched rays of anal fin; maxillary reaching to below front part of 

 eye; dorsal rays III — I, i, 7 or I, i, 8; anal rays I, i, 21 to I, i, 23; scales 

 44 to 48 Coleotropis blackbumi, new species. 



Genus ADENOPS Schultz 



Adenops Schultz, Proc. U. S. Nat. Mus., vol. 98, p. 34, 1948. (Genotype, 

 Adenops analis Schultz.) 



This genus has the premaxillary dilated posteriorly; premaxillary 

 or gape of mouth a little concave at side; rictus restricted by a 



