206 MEMOIRS OF THE CARNEGIE MUSEUM 



tip, tuberculate above, reaching the eye; premaxillary band of teeth .66 of the 

 length of the eye, the teeth minute; gill-openings reaching to below the eye, the 

 space between them equal to the eye. 



Distance from snout to dorsal 3.66 in the length; the spine an orbital diameter 

 shorter than the head, with short sharp teeth along its concave anterior margin, 

 the posterior margin smooth; caudal emarginate; origin of anal equidistant from 

 base of middle caudal rays and the anterior margin of the eye, its first rays thick^ 

 ened, osseous; ventrals emarginate, reaching to the third anal ray; pectorals sub- 

 falcate, the first ray not pungent, smooth on both margins, reaching the first or 

 fifth ventral ray. 



Steel-blue above, lighter below; dorsal spotted; upper surface of pectoral and 

 anterior ventral rays steel-blue, the membranes white with dark spots; caudal 

 margined with light ; a submarginal dark band shading into the color of the caudal 

 peduncle. 



Bleeker's figure was based on his smaller specimen, and the markings are still 

 visible on the fins. The barbel is however too long, not reaching the eye. 



77. Ageneiosus marmoratus sp. nov. (Plate XXII, fig. 1.) 



Type unique, a female, 175 mm. Creek below Potaro Landing. (Carnegie 

 Museum Catalog of Fishes No. 1710.) 



Readily distinguished by its conspicuous markings and short anal. 



Head 3.33; depth 5; D. 1,6; A. 29; V. 8; P. 16; Br. 10; eye 3.5 in snout, 6.3 

 in the head, 4 in the interocular space ventrad. 



Head wedge-shaped, much depressed, the profile nearly straight and but little 

 ascending; snout parabolic, the gape of the mouth very long, about three times as 

 long as the eye; fontanel extending to the anterior margin of the eye, its groove 

 to the posterior margin; premaxillary band of teeth half as wide as the eye, of 

 nearly uniform width to near the posterior end of the band; maxillary barbel not 

 reaching the rictus; gill-membranes free to below middle of the eye, the distance 

 between the clefts not equal to the eye; distance from snout to dorsal spine 3 in 

 the length; caudal emarginate; origin of anal but very little nearer base of pectoral 

 spine than to base of middle caudal rays; first dorsal and pectoral rays not pungent, 

 smooth on both margins. 



. Sides light, with spots and streaks of slaty; upper part of sides with five large 

 dusky spots margined with darker, not meeting on the middle line; dorsal black, 

 with a light band at base and another a little higher up; bases of caudal and anal 

 colored like the sides, then a broad black band, then narrowly margined with 

 hyaline; pectorals and ventrals black above, with a light band at the base. 



