El i i- : 'I'm I'l vi in \i \i.vkm.\a i ii 3. 393 



15. Chaenothorax semiscutatus (Cope). 



Corydoras semiscutatus Cope, Proc. Acad. Nat. Sci. Phila., 1 s 7 1 , 280, pi. 6, fig. 1 



(Ambyiacu Ri> 

 Cheenothorax semiscutatus Eigenmann, Rept. Princeton Univ. Exp. Patagonia, III, 



IQIO. 



No specimens. 



16. Chaenothorax eigenmanni 1 sp. nov. (Plate XXVI, fig. 2.) 



554.? C. M. Type, 51 mm. Caceres, May 26, 1909. Coll. Hasc- 



mau. 

 354;, C. M. Cotype, 55 mm. Caceres, May 26, 1909. Coll. 



1 (aseman. 



Head 2.9 to 3; depth 2.7; width 5; D. I, 12; A. 1. (> or 7; P. I, 7; 



24 

 lateral plates ; eye 3.5 in 3.7 in tin- head, 1.7 in the interorbital. 



2 2 



( ompressed throughout, dorsal profile only slightly arched from 

 the snout to the base of the dorsal plate. Scutes leaving a naked 

 area along the ventral side, and along the dorsal side in front of the 

 adipose. Coracoid processes reaching backwards almost to the 

 ventral and not expanded on the breast, leaving a naked area equal 

 to the eye in width in front of the ventral-. 



Entire snout and suborbitals unmailed. Eyes lateral, interorbitals 

 slightly convex; fontanel long, 1.5 times the eye, not quite reaching 

 the nares in front, just reaching the base of the occipital process 

 behind. Occipital process weak, reaching little more than half the 

 distance from its base to the dorsal. Eye 2.5 in the pointed snout. 

 Mouth small. A pair of equal barbies at the rictus, reaching hack 

 to the vertical from the middle of the eye or a little beyond, fused 

 at the base tor a distance of half the length of the eye. A pair of 

 short barbels, two-thirds the length of the eye, at the symphysis. 



Scutes almost entirely covering the sides. One very small azygous 

 plate just in front of the adipose. The distal hall of the exposed 

 parts of the scutes roughened with short backwardly directed spines. 



Dorsal spine equidistant from the snout and the upper caudal 

 lobe; slender, curved backward-; smooth in front, toothed behind; 

 1.3 to 1.4 in the head; about equal to the first ray-. Base of the dorsal 

 a little less than the he, id: lasl dorsal rays reaching the adipose. 



4 Xamecl for Dr. C. H. Eigenmann, under whose care and direction this paper 

 and my paper on the genera Hemigrammus and 1 1 y flu have been written. 



