146 FIELD COLUMBIAN MUSEUM ZOOLOGY, VOL. VII. 



rather robust; top of head nearly flat; interorbital 1.7 to 1.8 in head; 

 snout 3.7 to 4.0; diameter of eye 2.5 to 2.7; origin of dorsal slightly 

 be"hind that of anal, and slightly nearer tip of caudal than end of snout ; 

 midway between base of caudal and base of pectoral fin, its distance 

 from tip of snout 1.5 to 1.6 in body; pectoral fin reaching slightly past 

 base of ventrals, 1.3 in head ; depth of caudal peduncle 1.5 in head. 



Color greenish olive, middle of each scale with a dark spot forming 

 longitudinal lines along rows of scales ; females with no bars or lateral 

 band ; males with a broken lateral band crossed by rather indistinct 

 bars ; dorsal fin in both sexes with a row of black dots near its base, 

 and with second row at about basal third of fin, other fins plain. 

 Among the specimens from San Jose are two males, length of each 31 

 mm.; anal fin very long, 2.46 in body. The smallest female in the 

 collection is 37 mm. in length. Dr. Alfaro states that this species 

 feeds on the larvae of mosquitoes. 



Turrialba, 600 meters (i), 50 mm.; Pacific side (2), 45 mm.; San 

 Jose (16), 31 to 58 mm.; Quebrada de los Negros (i), 59 mm.; San 

 Isidro (i), 56 mm. 



Gambusia terrabensis Regan. OLOMINA. 



Type No. 6227, F. M. N. H.; length 52.5 mm. ; Los Canas, Alajue- 

 la, Costa Rica. 



Head 4; depth 3. 3; D. 10; A. 8; scales 28. Body robust; top of 

 head flat; interorbital 1.7 in head; snout short 3.7 in head; diameter 

 of eye 2.9; origin of dorsal over that of anal, its distance from tip of 

 caudal slightly greater than from tip of snout ; its distance from tip of 

 snout 1.7 in body; pectoral not reaching ventrals, 1.3 in head; depth 

 of caudal peduncle 1.5 in head. 



Color greenish olive, edges of scales black; no trace of lateral band 

 or bars ; dorsal fin with interradial membranes black ; anal fin with a 

 black spot on base of its middle 5 rays to tip of 2d and 3d rays, other 

 fins plain. Except in color markings this species much resembles the 

 former. Los Canas, Alajuela, Costa Rica, 900 meters (5), 52.5 and 

 55 mm. Collected June 19, 1907. 



Platypoecilus tropicus sp. nov. 



Type No. 6027, F. M. N. H.; length 63 mm.; Turrialba, Costa 

 Rica. 



Head 3.6 to 3.8; depth 3.2 to 3.5; D. 9 or 10; A. 8; scales 28. 

 Body robust; dorsal region slightly elevated; top of head slightly 

 convex; interorbital 1.9 to 2.0 in head; snout 3.6 to 4.0; diameter of 



