1906.] FRESH- WATER FISHES OF TRINIDAD. 383 



above about the seventh anal ray ; when laid back, in the female 

 not nearly reaching the caudal, in the adult male extending well 

 beyond the base of caudal. Anal 25-30, commencing at or a little 

 behind the middle of the length of the fish ; last ray, when laid 

 back, in the female not reaching the caudal, in the adult male 

 extending well beyond the base of the caudal. Pectorals and 

 venti-als extending to or nearly to the origin of anal ; ventrals 

 7-rayed. Caudal deeply forked, the lobes equal in the female, the 

 lower considerably ^Droduced in the adult male. Caudal peduncle 

 1|— 2 as long as deep. Olivaceous, with silvery reflections; a 

 blackish stripe along the middle of the side ; fins pale. 

 14 exi^imples, measuring up to 45 mm. in total length. 

 The genus StevarcUa was founded either on females or on very 

 young males, with the operculum ending in a short pointed process 

 and the fins not produced. Corynopoma included males of small 

 size, with the opercular pi-ocess short and the fins moderately pro- 

 duced, whilst Nematopoma was for the fully developed males. 

 LUtken pointed out that these supposed generic diSerences were 

 to be fovind in examples of the same species, according to the size 

 of the specimen taken. These changes are now found to be con- 

 fined to the males, and I see no reason to believe that more than 

 one species has formed the basis of Dr. Gill's descriptions. This 

 genus has only been recorded from Trinidad, 



"The 'Swallow-tailed Sardine' is faii-ly plentiful in the Tacarigua 

 River. Some have a peculiar pair of ' paddles ' attached to the 

 gill-covers, whilst others have no trace of them nor do they have 

 the exaggerated fins which the ones with ' paddles ' possess. They 

 are caught in company and are, presumably, the sa,me species. 

 The scales are faintly defined, generally silvery ; the back is 

 translucent greenish," 



4. Tetragonopterus t^eniurus Gill. (Plate XXII, fig. 4.) 



Depth of body 3-3^ in the length, length of head 4-4i. Snout 

 much shorter than eye, the diameter of which is 2| in the 

 length of head and a little greater than the interorbital width. 

 Maxillary extending to below the anterior | of eye, with a more 

 or less evident series of small teeth. Scales 38 p, 5 between 

 latei-al line and root of ventral fin ; lateral line complete. Dorsal 

 10, with 8 branched rays, its origin a little nearer to tip of snout 

 than to base of caudal ; anterior rays longest, nearly as long as 

 the head. Anal 29-31, with 26 to 28 branched rays. Pectoral 

 extending beyond base of ventral ; ventrals originating in advance 

 of the dorsal, extending to the anal. Caudal fox-ked. Caudal 

 peduncle as long as, or a little longer than deep. Olivaceous or 

 greenish above, silvery below ; a silvery longitudinal band fi-om 

 operculum to base of caudal ; a more or less distinct dark humei-al 

 spot ; a black longitudinal band on the middle caudal rays, edged 

 with yellow above and below. 



Here described from two specimens from Trinidad, 60 and 



