419 



inches, lines. 



Total length 5 5 



Height of the body 1 4 



Length of the head 1 2 



Width between the orbits 5^ 



Diameter of the eye 3^ 



Height of the dorsal 11 



Height of the anal 7 



There can be no doubt that this is quite a different species from 

 Anodus alburnus, described and figured by Mliller and Troschel in 

 the 'Horse Ichthyologicee,' The difference from Curimatus gilberti, 

 figured by Quoy and Gaimard, and insufficiently described by Valen- 

 ciennes, must be rather inferred, by help of the figure of Anodus 

 alburnus. Valenciennes describes it as a fish of entirely the same 

 form as A. alburnus ; therefore it is very improbable that our spe- 

 cies is identical with it, as it has the back very little elevated (as in 

 Leuciscus vulgaris), the dorsal fin much lower and situated far more 

 backwards, so that its end falls vertically as much behind the ventral 

 as its origin before it. The somewhat greater number of the scales 

 of the lateral line corresponds with these differences. 



7. Prochilodus humeralis, n. sp. 



D. 12. A. 11. V. 10. L.lat. 33. L. transv. b/7. 



The total length is 3f times the height of the body, and nearly 

 five times that of the head. The width between the eyes is one-half 

 the length of the head, or nearly twice the diameter of the eye ; the 

 end of the dorsal falls vertically above the end of the base of the 

 ventral. Back greenish, sides and belly yellowish ; each longitudinal 

 series of scales with a shining streak. A black spot behind the 

 shoulder on the fourth, fifth, and sixth scales of the lateral line. No 

 spot on the root of the tail ; dorsal dotted with blackish posteriorly ; 

 the other fins immaculate. 



Hab. Western Andes of Ecuador. 



inches, hnes. 



Total length 6 



Height of the body 1 7 



Length of the head 1 3 



Width between the orbits 7i 



Diameter of the eye 4 



Length of the third dorsal ray 1 



Length of the third anal ray 10 



8. Chalceus alburnus, n. sp. 



D. 11. A. 35. V. 8. L.lat. 60. L. transv. 13/5. 



The height of the body is one-fifth of the total length, the length 

 of the head one-fourth. The width between the orbits is rather 

 more than that of the eye, and one-fourth the length of the head. 

 The snout is produced, and equals \\ diameters of the eye. Anterior 

 teeth rather small : several of the lateral teeth of the mandibula much 



