418 



prominences on the tongue, nor distinguish the eyes. The vent is 

 close to the posterior extremity of the body, which is bent down- 

 wards over it. 



The colour is a blackish- ash ; there is a whitish blotch between 

 every pair of folds all along the side of the body. 



inches, lines. 



Total length 34 6 



Greatest diameter of the body 0 4% 



Length of the head 0 8£ 



Width of the head 0 5 



Length of the cleft of the mouth 0 6 



PISCES. 



1. Lembus maculatus, Gthr. Acanthopt. Fishes, i. p. 505. 



2. Chromis rivulata, n. sp. 



D. f'. A. J. L. lat. 28. L. transv. 3/9. 



Nape of the neck convex ; the upper profile of the head is straight, 

 abruptly descending. The total length is three times the height 

 of the body, and 3f times the length of the head. The width be- 

 tween the orbits equals 1^ diameters of the eye. The posterior 

 dorsal and anal rays reach to the middle of the caudal, if laid back- 

 wards, and the ventral to the second anal spine. Greyish-green, with 

 broad dark vertical bars, less distinct with age. A black blotch 

 below the lateral line, corresponding to the last four dorsal spines ; 

 prseorbital and cheeks with oblique, waving, bluish, shining silvery 

 streaks ; the scales of the operculum and of the anterior part of the 

 body with spots of the same colour. Dorsal fin with dark longi- 

 tudinal streaks ; ventral and anal greyish ; pectoral and caudal colour- 

 less. — Several specimens of different ages ; the largest 4 inches long. 



3. Leriasina bimaculata, Cuv. et Val. 



4. Macrodon tareira, Cuv. et Val. 



5. Leporinus frederici, Bloch. 



6. Anodus troschelii, n. sp. 



D. 12. A. 10. V. 9. L.lat. 46. L. transv. 7/8. 



The total length is four times the height of the body, and 4f times 

 the length of the head. The width of the space between the eyes is 

 not quite one-half the length of the head ; the diameter of the eye 

 is one-fourth of it. The height of the dorsal is much less than the 

 length of the head, and its origin corresponds to the fourteenth scale 

 of the lateral line ; the base of the ventrals falls vertically below the 

 middle of the dorsal. Silvery, back greenish ; a black spot on the 

 root of the caudal, 



Hab. Western Andes of Ecuador. 



