ioo Field Columbian Museum — Zoology, Vol. V. 



mittent organ; teeth all pointed, arranged page 



in bands; species viviparous, the young of 

 moderate or large size at birth. 

 i. Eye normal, the pupil not divided by a 

 partition; dorsal fin inserted more or less 

 behind the front of the anal. 

 j. Jaws not produced into a beak; lower 

 jaw prominent, longer than the upper; 

 the males much smaller than the females, 

 k. Dorsal fin long, of 14 to 16 rays; anal 



short Pseudoxiphophorous 127 



kk. Dorsal fin short, of 6 to 10 rays; anal 

 fin short. 



I. Alimentary canal less than twice length 

 of body. 



m. Anal fin not falcate, its first three 



rays not produced, the longest being 



less than the length of head Gambusia 128 



mm. Anal fin falcate, its first three rays 



much produced, the longest longer 



than the head Paragambusia 133 



II. Alimentary canal more than twice the 



length of the body Glaridichikys 134 



jj.Jaws produced into a moderate beak; 



dorsal and anal short, each of 9 to 11 rays . .Beloncsox 135 

 ii. Eye divided into two portions by a hori- 

 zontal cross partition; vertical fins short, 



of 9 to 11 rays Anableps 135 



aa. Intestinal canal elongate, usually coiled on 

 ventral and right side, with numerous convolu- 

 tions ; dentary bones loosely joined ; teeth mov- 

 able; species chiefly mud-eating, 

 n. Outer series of teeth bicuspid, with villi- 

 form teeth behind them ; anal fin of the male 

 with first five or six rays of anal fin short 

 and stiff and separated from the rest of the 

 fin by a notch; species viviparous, the young 

 of large size when born. 

 o. Body robust, oblong, depth 3 to 4 in length 

 of body; gill rakers long and slender, 35 to 

 40 on the first gill arch; vertebra? 19+17 

 = 36 Goodea 136 



