NEW SOUTH-AMERICAN FISHES. 



667 



2. Ch^tostomus palmeri, sp, n. (PI. LXXV. fig. 3.) 

 Ne<arest to C.fischeri Steind. Depth of body ^ in the length, 



length of head il. Head a little longer than broad and nearly 

 twice as long as deep. Diameter of eye 6| to 8 in length of head, 

 interorbital width 3 to 3^, length of snout 1| to 1|. Length of 

 mandibular ramus equal to interorbital width. Interoperculum 

 with 2 or 3 spines, 24 scutes in a longitudinal series, 6 or 7 

 between dorsal and adipose fin, 11 between anal and caudal. 

 Dorsal I 8 ; first ray | to | the length of head, last | as long ; 

 length of base equal to distance from posterior pait of spine of 

 adipose fin. Anal I 5. Pectoral spine just reaching base of 

 ventral. Caudal peduncle 2^ times as long as deep. Coloration 

 uniform ; dorsal and caudal with or without series of spots on 

 the rays. 



Two specimens, 75 and 95 mm. in total length, from the Rio 

 Tamana, Eio San Juan, Choco, S.W. Colombia., collected by 

 Mr. G. Palmer. 



3. Ch.etostomus lepturus, sp. n. (PI. LXXV. fig. 1.) 

 Depth of body 5^ to 6 in the length, length of head 3| to 3|. 



Head nearly as broad as long and almost twice as long as deep. 

 Diameter of eye 8 to 9| in length of head, interorbital width 

 3 J- to 3 1, length of snou^t'lS to If. Length of mandibular ramus 

 equal to interorbital width. Interoperculum with 5 to 8 spines. 

 25 scutes in a longitudinal series, 6 or 7 between dorsal and 

 adipose fin, 11 or 12 between anal and caudal. Dorsal I 8; first 

 ray nearly as long as head, last |- to | as long ; length of base 

 equal to or slightly more than its distance from adipose fin. 

 Anal I 5. Caudal obliquely emarginate. Caudal peduncle 3| to 

 4 times as long as deep. Coloi-ation as in G. marginatus Regan, 

 from which this species differs especially in the form of the 

 dorsal fin and the more slender tail. 



Three specimens, 135 to 215 mm. in total length, from the Rio 

 Tamana,, Rio San Juan, Choco, S.W. Colombia, collected by 

 Mr. G. Palmer. 



4. Ch^tostomus paucispinis, sp. n. (PI. LXXV. fig. 2.) 

 Depth of body 5 in the length, length of head ^. Head as 



broad as long and 14 as long as deep. Diameter of eye 8 in 

 length of head, interorbital Avidth 3, length of snout 1|. Inter- 

 operculum with 2 spines. 24 scutes in a longitudinal series, 

 6 between dorsal and adipose fin, 10 between anal and caudal. 

 Dorsal I 9 ; first i^ay a little less than | length of head, last f as 

 long ; length of base ecjual to distance from tip of spine of adipose 

 fin. Anal I 5. Pectoral spine extending to base of ventral. 

 Caudal very slightly emarginate. Caudal peduncle 2^ times as 

 lono- as deep. Back with dark cross-bars ; dorsal fin with series 

 of spots on the rays ; tips of all the fins i^eddish. 



A single specimen, 90 mm. in total length, from Tado, Rio 

 San Juan, Choco, Colombia, collected by Mr. G. Palmer. 



44* 



