NO. 1503. AMAZON FISHES— EIGENMANN AND BEAN. 663 



contained li times in its distance from the dorsal. Anal emarginate; 

 the highest branched ra}- is 2i times as long as the last. Pectoral 1| 

 in head; ventral much longer than pectoral, equal to its distance from 

 the base of the pectoral, 1| in head. Caudal deeply forked, the lobes 

 prolongated in filaments. Caudal peduncle 2^ times as long as deep. 



Silvery; darker above. 



Length of specimen to end of middle caudal rays, 260 mm. 



This species is very nearly allied to, if not identical with, jilaiynema 

 of Boulenger, from which it differs onl\^ in the size of the fins. 

 Brachyplatystotna platynehta may be referred to this subgenus. 



ry/>f.-Cat. No. 52571, U.S.N.M. 



PLATYSTOMATICHTHYS STURIO (Kner). 



■ Three specimens. 



DORAS DORSALIS Cuvier and Valenciennes. 



One specimen. 



TRACHYCORYSTES GALEATUS (Linnaeus). 



Three specimens. 



PSEUDAUCHENIPTERUS NODOSUS (Bloch). 



Four specimens. All females. One with mature eggs. Dark blue 

 above, extending on the sides to a greater or less extent. The wav}^ 

 lateral line white; free from pigment. Caudal margined with black; 

 the upper lobe with a more or less distinct black streak. Dorsal spine 

 with a large swelling at the base. 



AGENEIOSUS UCAYALENSIS Castelnau. 



Ageneiosus mil itar is CvviKR and Valenciennes, Hist. Nat. Poiss., XV, 1840, p. 2o2. 

 Ageneioms militaris, Valenciennes, Voy. d'Orbigny, IX, 1847, atlas, II, pi. iv, 



' fig- 1. 

 Ageneiosus ucayalensis Castelnav, Anini. Am. Sud., XLIX, 18.55, pi. xvii, tig. 2. 

 Ageueiosus militaris, Kner, Sitzb. Ak. Wien, XXVI, 1857, p. 437. 

 Ageneiosus militaris, Gunther, Cat. Fish. Brit. Mus., V, 18H4, p. 191. 

 Ageneiosus valenciennesi Bleeker, Silnres de Suriname, 1864, p. 82 (based on 



Valenciennes). 

 Ageneiosus valenciennesi, Eigenmann and Eigenmann, Proc. Cal. Acad., 2d 8er., I, 



1888, p. 150. 

 Ageneiosus ucayalensis, Eigenmann and Eigenmann, Proc. Cal. Acad., 2d Ser. I, 



1888, p. 150. 



We have before us five specimens. Two are males measuring 190 

 mm. and 180 mm., and the other three are females, 200, 230, and 270 

 mm. long. It is very probable that these belong to the same species. 

 The males apparently represent the ^1. valencUnn'sioi Bleeker, while 

 the females represent the A. ucayalensis of Castelnau. 



