THE CATFISHES OF VENEZUEIA — ^SdTULTZ 267 



the good fortune to collect 29 specimens of a new species in the Lago 

 Maracaibo Basin. This is the first record of this subfamily in northern 

 South America. 



Eigenmann (Mem. Carnegie Mus., vol. 7, No. 5, p. 369, 1918) 

 suggested that Tridens brevis should probably be placed in*a separate 

 genus. Thus Myers created the genus Tridentopsis and said, "I feel 

 justified in formmg a new genus for brevis and Pearson's fish, which I 

 provisionally recognize as a distinct species." Thus brevis, because 

 of its inadequate description with no figure, has been shifted about. 

 Now I feel justified in view of new material in putting brevis into still 

 another genus. 



This new genus, Tridensimilis, may be distinguished from all other 

 members of the subfamily Tridentinae by the following combination 

 of characters : Opercular spines 6 in number and interopercular spines 

 4 to 6, these patches of spmes separately movable and distinctly 

 separated; gill membranes joined across isthmus with a broad free 

 fold; eyes lateral; depth of body 6 to 8, head 5 to 6K in standard length, 

 teeth small, curved, conical, in three separate rows above; dorsal rays 

 ii or iii (probably iii), 7 or 8; anal ii or iii (probably iii as the first simple 

 ray is rudimentary) 18 to 21; pelvic i,4; pectoral i,5; branchiostegals 

 5; nasal barbel absent. 



Other characters are those of the new species, Tridensimilis vene- 

 zuelae, described below. 



Genotype. — Tridensimilis venezuelae, new species. 



TRIDENSIMILIS VENEZUELAE, new epecies 



Plate 6, C 



Holotype. — U.S.N.M. No. 121290, a specimen 19.5 nrmi. in standard 

 length (total length 23.5), collected by Leonard P. Schultz, March 2, 

 1942, in the Rio Negro below the mouth of the Rio Yasa, Maracaibo 

 Basin. 



Paratypes.~\] .S.1<1 M. No. 121291, 28 specimens, 13.8 to 20.5 mm. 

 in standard length and 16.5 to 24 mm. in total length, collected along 

 with the holotype and bearing the same data. 



Description. — Based on the holotype and paratypes listed above. 

 Measurements of the holotype and one paratype, expressed in hun- 

 dredths of the standard length are recorded below, first for the hole- 

 type, then for the paratype in parentheses. Standard length (in 

 mm.) 19.5 (20.4). 



Length of head 16.9 (15.7); width of head across eyes 14.9 (15.7) 

 greatest depth of body 16.9 (17.1); length of snout 8.72 (8.82) 

 diameter of eye 4.62 (3.92); width of interorbital space 8.72 (9.32) 

 postorbital length of head 6.16 (5.88) ; length of longest ray of anal fin 

 6.66 (7.35) ; longest ray of dorsal fin 8.20 (8.33); longest ray of pelvics 



