224 PROCEEDINGS OF THE ACADEMY OF [Apr., 



two in eye. Anal with long, straight base, anterior branched rays 

 slightly longer, and base of fin 2| in combined length of head and 

 trunk. Caudal (damaged) broad, and apparently forked. Pectoral 

 with long and nearly straight spine, its surface with fine lengthwise 

 striae, its outer edge smooth and its inner edge serrated, when 

 depressed extending nearly to ventral. Latter broad, first ray 

 straight. Vent about midway in length of ventral. 



Color in alcohol dull brownish generally, with grayish shade on 

 back and upper portions. Lower portions of body slightly paler 

 than upper. From shoulder towards middle of upper caudal lobe 

 pale dusky-gray streak, and another below and parallel from ventral 

 origin. Barbels brownish, also eyes. Fins all brownish. 



Length 163 mm. (caudal tips damaged). 



Type, No. 21,484, A, N. S. T., Ambyiacu River, Ecuador. J. 

 Hauxwell. Presented by E. D. Cope. 



This species is related to Auchenipterus nuchalis, but differs at 

 once in its deeper body. A. nuchalis has the greatest body depth 

 4f to 5, and mental barbels extending a little beyond middle of 

 pectorals. 



(Named for the Ambyiacu River.) 



Auchenipterus braohyurus (Cope). 



Euanemus hracJujurus Cope, Proc. Amer. Philos. Soc, XVII, 1878, p. 076. 

 Peruvian Amazon. 



No. 21,552, A. N. S. P., type of E. brachyurus Cope. Peruvian 

 Amazon. J. Orton. Presented by E. D. Cope. 



Ageneiosus porphyreus Cope. 



Trans. Amer. Philos. Soc, (2) XIII, 1867, p. 404. Surinam. 



No. 8,389, A. N. S. P., type. Surinam. Also a small example 

 from same locality. Likely A. guianensis Eigenmann from Wismar 

 in British Guiana may be found identical. 



Ageneiosus brevifilis Valenciennes. 



One example from the Peruvian Amazon in rather poor condition. 

 If marked as described by Bleeker, scarcely any traces of the color- 

 pattern remain. -Dr. Steindachner next^^ figures the species from 

 Rio Purus, with the pectoral not reaching the ventral. His examples 

 were from Surinam, the Amazon and Paraguay, measuring 175 to 

 341 mm. Bleeker's examples were 236 to 275 mm. Eigenmann^^ 

 had an example 445 mm. from Lama Stop-off in British Guiana, and 



" Annal. Naturh. Hofmus. Wien, 1910, p. 403, PI. 8. 

 12 Mem. Carnegie Mus., V, 1912, p. 205. 



