FISHES FROM ECUADOR AND PERU—STARKS. 777 



bande arg-entee le long du corps, se terminant en une tache noire sur 

 la queue, a la base de la caudale; en avant, sur la ligne laterale, deux 

 taches noires plus ou moins nettes; ces taches manquent parfois. 



25. TETRAGONOPTERUS RUTILUS Jenyns. 



A single specimen, 165 mm. in length, collected in the Rio Perene, 

 on the east slope of the Andes in Peru, appears to be referable to this 

 species. It differs from T. peruanus in having the dorsal more ante- 

 riorly^ placed. The front of the dorsal is midway between the tip of 

 the snout and a distance behind the tip of the adipose dorsal equal to 

 a diameter of the pupil. The anal is one diameter of the eye behind 

 the base of the last dorsal ray, or nearly under the tip of the last dor- 

 sal ray. The ventrals are two-thirds of a diameter of the eye in front 

 of the dorsal. 



26. BRYCON ATRICAUDATUS Kner. 



Several specimens were taken at Payta and one at Eten, Peru. The 

 longest 15 cm. in length. 



Head, 3i in length without caudal; depth 3i. Eye, 4i in head; max- 

 illary, 2i; snout, 3|; interorbital space, •!. Dorsal, 10 or 11; anal, 28 

 or 29. Scales, 54 to 56; transverse series, 10+1+6. 



Lower jaw included; maxillary reaching to below middle of eye. 

 Gill rakers slender, the longest two-fifths of diameter of eye; 15 on 

 lower limb of arch. Origin of dorsal midway between nostril and 

 base of caudal; one diameter of eye behind base of ventrals. Anal 

 one-half of diameter of eye behind base of dorsal. Pectoral not quite 

 reaching to base of ventral, which does not reach to front of anal. 

 Caudal deeply forked. 



A dark, usually very definite humeral spot crosses the anterior end 

 of lateral line, the greater part of its area above the line. An incon- 

 spicuous blotch at base of caudal. 



Family STERN OPYGID^E. 



27. STERNOPYGUS iEQUILABIATUS (Humboldt). 



Several specimens collected at Guayaquil, the largest 53 cm. in 

 length. 



Depth of body, five-sixths to seven-eighths of length of head to 

 upper end of gill opening. Snout, contained 3 times in head; maxil- 

 lary, 4 to 41 times. Eye (between adipose eyelids), 5i to 6 times in 

 snout, 16 to 18 in length of head. Length of gill opening less than 

 length of snout by 1 diameter of eye. Fine movable teeth with 

 their tips only slightly projecting beyond the spongy dermal tissue are 

 set in broad bands on jaws; the upper band nearly straight and broadly 

 rounded at its ends; one-third as broad as long; the lower band crescent- 



