166 CALIFORNIA ACADEMY OF SCIENCES. 



the length of the adipose dorsal; pectoral spine serrated 

 on both edges, 1J in length of head. Uniform dark 

 above, lighter below. (Liitken.) labrosus 126. 



dd. Anal rays 17. Adipose dorsal equals anal. Body rather high 

 and compressed; head depressed; profile straight; width of the 

 head 2| in its length. Eye 6 in length of head, 2 in interorbital. 

 Upper jaw somewhat projecting; teeth in both jaws in shallow 

 and narrow bands. Maxillary barbel to anal; post-uiental bar- 

 bels to ventrals; mentals slightly shorter. Dorsal spine serrate 

 behind, little shorter than the pectoral spine which is serrated on 

 both margins; pectoral spine \\ in head. Head 4 in total length; 

 depth 5J. D. I, 6. A. 17. (Liitken.) valenciennis 127. 



cc. Intermaxillary teeth none; snout long, sub-conical, lips broad; 

 mouth small. Eye 5 in head; interorbital area little narrower than 

 eye; dorsal spine serrated behind, shorter than head; peAtoral spine 

 If in head. Adipose dorsal 4 in the length; maxillary barbels to 

 caudal; mental barbels to gill-opening; postmental to pectoral. 

 Head 4; depth 5J; D. I, 6; A. 12 or 13. (Liitken.) 



westermanni 128. 



bb. Length of the adipose fin 2j?-2f in the length; caudal lobes pro- 

 duced, twice as long as head; maxillary barbels extending much be- 

 yond tips of caudal. altipinnis 129. 

 an. Head granulated above but covered with a very thin skin; upper 

 anterior half of body with dark spots; anal emargiiiate. fur 130. 



120, Pimelodus eques. 



Pimelodus eques Miiller & Troschel, Schomburgk Brit. Guiana, 628, 

 1848 (in all rivers of Guiana); Miiller & Troschel, Horae Ich- 

 thyol. iii, 5, 1849 (Guiana); Giinther, Cat. Fish. Brit. Mus. v, 

 116, 1864 (copied); Steindachuer, SB. Ak. Wien, Ixxiv, 1876, 

 Ichthyol. Beitr. v, 99 (Amazon near Fonteboa; Teffe; Obidos; 

 Villa Bella; Jose Fernandez; Xingu; Tonantins; Hyutahy; Lake 

 Hyanuary); Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. i, 134, 

 1888 (localities mentioned by Steindachiier). 



Habitat: Brazilian Amazon and its tributaries and northward. 



The flat head and peculiar shape of the occipital crest, 

 the shape of the anal, etc., distinguish this from all 

 other related species. 



Body not as wide as deep at the shoulders, compressed 

 towards the caudal; head flat, depressed, its greatest 

 width li in its length, its greatest depth about 2|. En- 

 tire upper portion of head granulose or striate; fontanel 

 continued as a narrow groove to the occipital crest. 

 Tip of occipital crest emarginate, articulating with the 



