1903.] NATURAL SCIENCES OF PHILADELPHIA, 513 



Much compressed, back conspicuously elevated, the anterior profile 

 straight, the upper profile strongly arched, descending backward from 

 in front of dorsal. Eye greater than snout, about 3 in head, slightly 

 less than interorbital. Intermaxillary with six teeth in each side, each 

 with an inconspicuous median cusp and 3 to 4 graduated lateral cusps ; 

 the cusps of the teeth becoming more nearly of the same size and the 

 tooth rounded toward the side. ]\Iaxillary with 2 seven- to eight- 

 pointed broad-tipped teeth. Mandible with 4 broad, seven-pointed 

 teeth; the middle point is largest, the tip spatulate. A few small 

 teeth on the sides of the lower jaw. 



Origin of dorsal over origin of ventrals, slightly nearer tip of snout 

 than base of caudal, its highest ray about equal to the length of 

 the head. Caudal lobes longer than head. Pectorals reaching ven- 

 trals; ventrals not to anal. 



In alcohol : Lower half of body metallic-silvery, a silvery lateral band. 

 A conspicuous caudal spot continued on the base of the middle caudal 

 rays; a dark band at base of caudal. A dusky band on middle of 

 back behind anal. Dorsal without dark spot, its first membrane dark ; 

 other fins immaculate. In the co-types the anal reaches 22, the scales 

 34 or 35, head 34-4^. Eye 2f . 

 56. Odontostilbe trementinae sp. nov. 

 Type No. 9,987a (251 in part), 47 mm. Arroyo Trementina. 

 Co-types No. 9,987, 9 specimens (251 in part). Arroyo Trementina. 

 One other specimen was taken at Asuncion, and two others from'a 

 brook near the Arroyo Trementina. 



This species resembles H. peguira in the color of the" dorsal, [but 

 beyond this there is no similarity. 

 Depth 3; head 4; D. 11; A. 21; scales 6-34-4. 

 Two broad-tipped teeth on the maxillary, each with about 7 pomts. 

 Intermaxillary with 6 spear-tipped teeth on each side, each wdth a 

 large long median point and two or three short, graduated lateral 

 points. Lower jaw with about 9 three- to six-pointed teeth on the 

 sides, the first one large, the others small and decreasing in size back- 

 w^ard; about 6 broad teeth on the dentary, each with 3 lobes of equal 

 size, each lobe being indistinctly three-pointed. They appear as 3 

 distinct teeth. Maxillary reaching beyond anterior margin of eye. 



Dorsal equidistant from tip of snout and base of middle caudal 

 raj'S, behind the ventrals. Pectorals not to ventrals, ventrals not to 

 anal. 



In formalin : A conspicuous hastate caudal spot, extending forward 

 as a faint dark line to below the dorsal where it fades out, A dark 

 33 



