346 MEMOIRS OF THE CARNEGIE MUSEUM. 



the rami transverse, united. The genus differs from Stegophilus chiefly in the shape 

 of the caudal, which is emarginate instead of rounded, and in the number of oper- 

 cular spines. 



Key to the Species of Henonemus. 



a. Origin of dorsal equidistant from tip of caudal and interopercle; origin of ventrals nearly equidistant 

 from tip i >f lower caudal lobe and snout. 

 6. Sides plain, caudal spotted, last half of its lower lobe black; D. 10; A. 9. 



1. macrops (Steindachner). 

 66. Sides with a median series of spots, and smaller spots above them; tip of lower caudal lobe and 



an oblique band across the upper lobe black 2. punctatus (Boulenger). 



666. Sides with a regular series of spots, smaller spots above them; lower caudal lobe not black at tip, 



several obscure spots on dorsal, caudal and base of pectoral 3. taxistigmus (Fowler). 



an. Origin of dorsal equidistant from tip of caudal and occiput; origin of ventrals equidistant from bases 

 of caudal and pectoral; caudal with faint dusky spots; upper surface with dark spots; a series of 

 larger spots along the middle of the sides 4. intermedius (Eigenmann & Eigenmann). 



1. Henonemus macrops (Steindachner). 

 Stegophilus macrops Steindachner, Flussf. Sudam., IV, 1882, p. 28, pi. VI, fig. 



2-2a (Lake Manacapurii); Eigenmann & Eigenmann, Proc. Cal. Acad. Sci. 



(2), II, 1889, p. 55; Occasional Papers Cal. Acad. Sci., I, 1890, p. 344; Proc. 



U. S. Nat. Mus., XIV, 1891, p. 37. 

 Henonemus rnacrops Eigenmann, Reports Princeton Univ. Exped. Patagonia, III, 



1910, p. 401; Ribeiro, Fauna Bras., IV (A), 1912, p. 231. 



Habitat. — Lake Manacapuru. 



% 



Fig. 22. Henonemus macrops Steindachner. (After Steindachner.) 



Known from the types only, which are in the Vienna Museum. Head 5; 

 depth 5; D. 10; A. 9; P. 6; eye 3.4 in the head; width of head 1.25 in its length; 

 barbel scarcely more than half as long as the eye ; pectoral equals the head without 

 the snout; distance between caudal and origin of dorsal 1.5 in its distance from the 

 snout; origin of anal under the last dorsal ray; sides of head and body without spots; 

 lip of lower caudal lobe dark, the other fins plain. 



2. Henonemus punctatus (Boulenger). (Plate XL, fig. C.) 

 Stegophilus punctatus (Boulenger), Proc. Zool. Soc. Lond., 1887, p. 279, pi. XXI, 

 fig. 4 (Canelos); Eigenmann & Eigenmann, Proc. Cal. Acad. Sci. (2), II, 



