Fisher: Hvpophthalmid.i:, Diplomystid.^, Silurid^. 425 



extends along the anterior face of the anal lobe, is expanded at the tip 

 into a vesicle, and opens near the tip of the ray. 



In the specimens from Penedo, the dots of the back are much 

 coarser than in the specimens from Para; the caudal lobes plain. 



So. Auchenipterus nuchalis (Spix). 



6772a-c, C. M., three, 64-134 mm., ParA, Jan. 5-Feb. 7, 1909. Hase- 



man. 

 6774a, C. M., one, 208 mm., San Antonio, Rio Madeira, Nov. 3, 1909. 



Haseman. 

 7309c-/, C. M., six, 76-157 mm., Lagoa de Parnagua, Jan. 17, 1908. 



Haseman. 



In No. 6774a the dorsal is 1.7; pectoral spine seven times in the 

 length, not equal to its distance from the tip of the snout; outer ven- 

 tral ray longer than the pectoral; maxillary barbel extends to tip of 

 ventrals; pectorals dusky toward tips; ventrals pale. 



41, 43, 44 

 In7309a-/, head 4.75-5.25; depth 4.5-5 ; D. 1.7; A. — — — V. 13; 



maxillary barbel extending nearly or quite to tip of pectorals; ventrals. 

 sometimes reaching to the eighth anal ray. 



These specimens have uniformly seven dorsal rays. The sides are 

 plain; a dark streak along middle of back. Top of head peppered; 

 occipital dark; fins all pale, except sometimes the caudal, which may- 

 be tipped with dark. 



Subfamily Ageneiosin^. 

 81. Ageneiosus ucayalensis Castelnau. 



7132C-&, C. M., two, 205-about 270 mm., Manaos, Nov. 16, igog. 



Haseman. 

 7133^-g. C. M., seven, 140-174 mm.. Para, Dec. 27, 1909. Jan. 22, 



1910. Haseman. 



These specimens are like those described by Eigenmann & Eigen- 

 mann. South American Nematognathi, 1890, p. 306, except for the 

 depth of the band of premaxillary teeth, which is variable. In some 

 specimens the depth of the band is equal to the eye while in others it 

 is scarcely more than one-half the diameter of the eye. 



82. Ageneiosus dentatus Kner. 



7136a, C. AI., one, 94 mm., Berlin, Rio IMamore, Sept. 15, 1909. 

 Haseman. 



