136 THE CYPRINODONTS. 



lighter, as also lower surface of head. Centres of scales darker. Dorsal and 

 caudal with transverse series of small spots, often irregular, sometimes absent 

 An ocellate spot on the bases of the caudal rays in the upper lialf of the fin 

 is not always present. Pectoral and anal somewhat clouded in large speci- 

 mens. Top of head between the eyes darker. Longest example one and 

 three eighths inches. 



Para ; Gurupa. 



Rivulus mioropus. 



Plate III. Fig. 13, teeth. 



Fandulus micropus Steind., 1863, Sb. Ak. Wien, XLVIIT, 184. 



Rivulus micropus Gthr., 1866, Cat, VI, 327 ; Cope, 1878, P. Am. Phil. Soc, XVII, 695 ; Jor., 1887, 

 P. U. S. Mus., IX, 564 ; Eig., 1891, P. U. S. Mus., XIV, 64. 



Rivulus (Fuiif/ulus) micropus Steind., 1880, Deuk. Ak. Wien, XLII, 86. 

 Ilaplochilus Uartii Blgr., 1890, Ami. Mag. Nat. Hist., (6) VI, 190. 



B. 6; D. 8-9; A. 14-15; V. 6 ; P. 13-15; LI. 42-44 ; Ltr. 11; Vert. 

 14 + 18. 



Form rather elongate, compressed backward, depressed from the shoul- 

 ders forward, depth about two ninths of the length to the caudal. Head 

 broad, flattened on the crown, five and a half times in the length with the 

 caudal or four and a half without it. Snout broad, rounded, hardly as long 

 as the eye. Eye large, three and a half times in the head, twice in the fore- 

 head. Mouth medium, nearly horizontal ; upper jaw shorter ; symphyses 

 firm. Teeth simple, pointed, hooked, outer series larger, not in contact ; 

 inner in bands. Dorsal small, origin above hind part of anal, three fourths 

 of the distance from the snout to the base of the caudal. Anal larger, base 

 extending farther forward than that of dorsal and nearly as far backward. 

 Caudal broad, fan-shaped, regularly rounded, as long as head. Ventrals 

 small. Pectorals not large, with rounded margins. 



Olivaceous, darker on back and top of head, lighter to whitish beneath. 

 Centres of scales on flanks darker. Fins lighter with darker edges. Lower 

 lip darker. Dorsal fin with vermiculations or irregular series of small spots, 

 or uniform. Caudal in many cases with white edge above and below, occa- 

 sionally a black blotch in the white. Specimens of less than two inches are 

 lighter colored and have a light band more or less marked by blotches along 

 the back, while the dark in the middle of each scale on the flank forms vittK ; 

 a dark spot surrounded by white on the upper portion of the base of the tail 

 is not rare. As the individual grows darker the spot is undistinguishable. 

 Largest example three and one eighth inches. 



Trinidad ; Rio Negro. 



