392 PROCEEDINGS OF THE ACADEMY OF [June r 



Dorsal inserted about midway between hind pupil edge and 

 caudal base, second branched ray highest, and depressed fin extending 

 slightly over half way to caudal base. Anal inserted slightly behind 

 dorsal origin, reaches about halfway to caudal base when depressed, 

 and first branched ray longest. Both dorsal and anal form distinct 

 point in front at tip of second branched ray, and upper front edge 

 of each also slightly emarginate. Caudal with hind edge convex,, 

 each corner forming slight angle. Pectoral rather broad, extends 

 back opposite ventral origin. Ventral inserted about midway 

 between pectoral and anal origins, depressed fin reaching latter, and 

 first branched ray longest. Vent and genital orifice close before anal. 



Color when fresh in alcohol olive-yellow generally above, edges 

 of scales darker. Lower surface of head and belly pale to whitish. 

 Dorsal bright orange-yellow, edge gray and base broadly jet-black. 

 Caudal grayish, base yellowish. Pectoral pale olive. Anal and 

 ventral whitish, tinged with yellowish medianly. Broad dark brown 

 median streak down back and brownish line along lower surface of 

 caudal peduncle from anal to caudal base. Iris olive. 



Length 55 mm. 



Type, No. 45,391, A. N. S. P. (Female.) Rio Guapilis at Guapilis, 

 Costa Rica. July, 1915. D. E. Harrower. 



Also Nos. 45,392 to 45,394, same data, paratypes, all females. 

 They show: Head 3§ to 4; depth 3f to 4; D. i, 8; A. in, 7; scales 

 30 to 32 in lateral series to caudal base and 3 more on latter; snout 

 3 to 3| in head, measured from upper jaw tip; eye 2f to 2f ; inter- 

 orbital 2; length 25 to 46 mm. 



Allied with the preceding species in having the dorsal origin slightly 

 before that of the anal. It differs in the more elongate body. In 

 the small head it resembles P. -pittieri, though that species is said to 

 have the depth 2.6 to 2.8. The jaws are not so broadly truncate 

 as in Pcecilopsis generally, but have a more rounded appearance 

 laterally, as in Fundulus and allied genera. 



{Macula, spot; fero, to bear; with reference to the black basal 

 dorsal blotch.) 



Mollienisia sphenops tropica (Meek). 



Color of adult female generally olivaceous, under surface of head 

 and trunk paler, when fresh in alcohol. Along side of trunk each 

 scale with small obscure orange spot, producing lengthwise streaks. 

 Dorsal olive, base jet-black over good portion. Caudal and pectoral 

 dull olive. Anal orange, hind edge whitish. Ventral whitish. Iris 

 olive. Length 6Q mm. 



