616 



FISHES. 



both sides are united for a short distance, and not attached to 

 the isthmus. 



Inhabitants of Lake Titicaca and other elevated sheets of 

 water on the Cordilleras of Peru and Bolivia, between the 

 14th and 19th degrees of latitude, at an elevation of 13,000 

 and 14,000 feet above the level of the sea. Singularly, the 

 fishes of this outlying genus attain to a greater size than any 

 other members of this family, being about eight inches long 

 and comparatively bulky. They are considered a delicacy. 

 Six species. 



Jenynsia. — Cleft of the mouth small, developed laterally 

 and horizontally ; snout not produced. Both jaws with a series 

 of tricuspid teeth of moderate "size. Scales of moderate size. 

 The origin of the anal fin is, in both sexes, behind that of the 

 dorsal, although the anal of the male is modified into an intro- 

 mittent organ, in which scarcely any of the rays remain distinct. 



One species from Maldonado. 



Gambusia. — Cleft of the mouth developed laterally and 

 horizontally. Snout not produced, with the lower jaw more or 



Fig. 280. — Gambusia punctata, from Cuba. A. Male ; B. Female. 



less prominent. Both jaws with a band of teeth, those of the 

 outer series being strongest and conical. Scales rather large. 

 Origin of the anal fin more or less in advance of that of the 

 dorsal. Anal fin of the male modified into an intromittent 

 organ and much advanced. 



