98 MEMOIRS OF THE CARNEGIE MUSEUM. 



Head 3.6; depth 2-7/8; D. 12; A. 23; scales 6-37-4; 11 predorsal scales; eye 

 3-1/8 in the head, maxillary 3-1/8, interorbital 3; height of dorsal 1; height of 

 anal 1.4; depth of caudal peduncle 2.5; pectoral 1.25; ventral 1.4. 



Compressed, elongatel.y ovoid; mouth, short, jaws thin; lips thin; maxillary 

 reaching the eye; teeth broad, with seven denticles, of which the median largest; 

 maxillary with two similar teeth; suborbitals entirely covering cheek. 



Dorsal inserted nearly midway between tip of snout and end of adipose ; origin 

 of anal close behind vertical from end of dorsal, lowest edge of anal emarginate; 

 ventrals inserted slightly behind origin of dorsal, extending to anal. 



Margin of scales of back dusted, a patch of dusky dots above base of anal. 

 Base of caudal with a large rounded spot about as large as eye. A dark line con- 

 current with vertebral axis from behind shoulder to caudal. 



55. Odontostilbe melandeta Eigenmann. 

 Odontostilbe melandetus Eigenmaim, Mem. Carnegie Mus., Vol. V, 1912, p. 312, 



Plate XLIV, fig. 3 (British Guiana, probably Rockstone on the Essequibo 



river) . 



Range: British Guiana. 



1878, C. M., type, 27 mm.; 12160, I. U. M., two, paratypes, 27 and 35 mm. 

 British Guiana. Eigenmann. 



Known only from the types. This species is more cylindrical, its scales firmer, 

 its teeth smaller. It is quite possible that it represents the type of a distinct genus. 



Head 3.75; depth 3.6; D. 10; A. 21; scales 4-34 or 35-3. Eye 2.5-2.7 in 

 the head, interorbital but little narrower than the eye. 



Minute, compressed, head bluntish, mouth terminal; a median series of ten 

 scales in front of the dorsal. Maxillary very slender, reaching to below the eye; 

 maxiUary-premaxillary border as long as the eye; ten to fourteen teeth on the pre- 

 maxiUary, four to seven on the maxillary. 



Scales very regularly imbricate, with concentric, but without longitudinal 

 striae; lateral line complete, scarcely decurved; anal naked; base of caudal with a 

 few scales. 



Gills well-developed; anal deeply emarginate; pectorals not quite reaching 

 ventrals, ventrals not reaching anal. 



No chromatophores on the sides; scales of the back with marginal series of 

 chromatophores; a series of black specks along the base of anal; caudal peduncle 

 margined with black. 



