POECILIIDAE. 83 



little more regularly rounded; the larger of the black spots are a little more 

 than half the size of eye. 



In No. 3201, M. C. Z. 29640, the teeth are exactly as in the last specimen; 

 eye 2.09 in snout; snout 2.17 in gape. 



General color, dark chocolate brown, thickly covered with small pale spots 

 anteriorly, and sparsely posteriorly; numerous black spots, many as large as 

 eye on body, arranged in more or less regular transverse rows at least anteriorly. 



Uropterygius necturus (Jordan & Gilbert). 



Jordan & Evermann, Bull. 47, U. S. Nat. Mus., 1906, pt. 1, p. 404. 



Gymnomwaena neclurus Jordan & Gilbert, Proc. U. S. Nat. Mus., 1882, 6, p. 356. 



A specimen, No. 3377, 16 inches long from Acapulco. 



Descriptions of this species state that it has no posterior nasal rim or tube. 

 The specimen studied, however, has a prominent posterior nasal tube. All the 

 specimens entering into these descriptions were small and the length of the tube 

 in specimens of Uropterygius and "Scuticaria" seem to vary with the size or age 

 of the individual. The present specimen is in poor condition, is strongly com- 

 pressed laterally, fins showing only on the end of tail and confluent around it, 

 the dorsal extending about twice as far forward as the anal; eye 2.28 in the 

 snout; snout 2.62 in gape; teeth in two series on the sides of upper jaw meeting 

 at the symphysis, the outermost numerous and much smaller, inner long and 

 sharp; behind the inner row of teeth in front are two cross-rows of four each, very 

 long sharp teeth; mandible with two rows of teeth similar to those in upper jaw, 

 but the long sharp teeth are bunched and not in rows. 



Color in alcohol: — uniform dark purplish brown, no traces of markings 

 anywhere observable; the vertical fins yellowish. 



SILURIDAE. 



Sciadeichthys troscheli (Gill). 



Jordan & EvERMA^fN, Bull. 47, U. S. Nat. Mus., 1896, pt. 1, p. 122. 

 Sciades troscheli Gill, Proc. Acad. Nat. Sci. Phil., 1863, p. 171. 



One individual. No. 3142, 13| inches long from Panama anchorage. 



POECILIIDAE. 

 Poecilia sphenops Cdvier & Valenciennes. 

 Hist. Nat. Poiss., 1846, 18, p. 98 (1.30). Regan, Biol. Centr. Amer. Pisces, 1907, p. 102, pi. 13, fig. 1-7. 



Twenty-five specimens I to ll inches long from one mile south of Panama 

 City, October 23, 1904. M. C. Z. 29433 (10 specimens). 



