1916.] \\l'i RAL SCIENCES OF PHILADELPHIA. I:;.") 



graduated down, depressed fin extending about I to caudal ba 

 Caudal with hind edge convexly rounded. Pectoral long, with 

 wide base, reaches back nearly opposite anal origin. Ventral small, 

 inserted little nearer anal than pectoral, and not quite reaching 

 former. 



Color in alcohol largely brownish, paler below, each -rale on back 

 with cluster of dark pigment dots at pockets. Iris slaty with dark 

 pigment dots. Dorsal rays each with median brownish spot and 

 another midway toward base. Median caudal rays with three or 

 four brownish spots, forming irregular transverse bars, especially 

 evident when fin closes. Outer portions of anal rays with few 

 brownish pigment spots. Except as noted, all fins pale or transparent. 



Length 35 mm. 



Type No. 6,818, A. N. S. P. Panama. J. A. McNiel. 



Only the above example, a female, known. It is close to the 

 figure of G. nicaraguensis Giinther, 7 except the latter shows the 

 dorsal and caudal with more darker spots on the rays, especially 

 terminally. The prepectoral scales smaller, and a dark spot little 

 smaller than the eye above post ventral region. Possibly this figure 

 may refer to Gambusia dovii Regan, 8 as Giinther's G. nicaraguensis 

 was based on "several females 1| or 2 inches long presented by 

 Captain Dow. " Now G. dovii Regan differs in having the depth 3f 

 and the head 3f, eye 3^, 32 scales, dorsal rays 7, and interorbital If. 

 It is based on a single female 33 mm. long. 



G. cascajalensis Meek and Hildebrand 9 differs in the head 3 T V to 

 3f, depth same, D. i, 6, A. n, 7, scales 26, smaller eye (2^ to 3^), 

 and the coloration. 



Three other species, G. latipundata Meek 10 and Hildebrand, G. cana 

 Meek and Hildebrand, 11 G. <l<irienensis Meek and Hildebrand, 12 all 

 have smaller head, lesser depth, fewer branched rays, more scales, 

 smaller eye, different coloration, etc. 



(Named for J. A. McNiel, who collected fishes in Panama many 

 years ago.) 

 Gambusia nicaraguensis Giinther. 



Orizaba, Mexico. * 



7 Tr. Z. Sor. London, VI, 1868, p. 182, PI. 82, fig. 3. Lake Nicaragua. 



8 Proc. Z. Soc. London, 1913, p. 986. Lake Nicaragua. 



9 Field Mus. Pub. Kili, Zool. Ser. X, No. 8, I'M:;, p. sii. Rio Cascajal, Atlantic 

 slope of Panama. 



10 L.c, p. 87. Arrijan, Pacific slope of Panama. 



11 L.c. Rio Satiganti, ('ana, Pacific slope of Panama. 



a L.c, p. 88. Rio Capet i, Tuyra River basin, Pacific slope of Panama. 



