Eigenmann: Collections of Fishes from Paraguay. 117 



Body short and deep ; ventral outline almost straight to base of 

 anal ; profile steep to nostrils, rounded at base of dorsal spine ; head 

 short, slightly deeper than wide, its depth equal to its length. Inter- 

 orbital region convex. Occipital region steep and convex. Fontanel 

 an oval opening somewhat shorter than the eye, situated in a groove 

 iy 2 times as long as the eye. Eye large, if£ in the snout, 3 in the 

 head, i}$ in the interorbital ; snout short, rounded. Barbels all 

 connected by a membrane, those of the maxillary extending to gill- 

 openings, with a few cirri on their outer margins ; gill opening ex- 

 tending forward to about % the distance of the eye. Coracoid proc- 

 ess exposed, striate. Humeral process broad and long and with a 

 strong keel, its surface striate. A few imbedded scutes in front of a 

 large scute which is connected with the dorsal plate ; the following 

 lateral scutes much lower, each with a large median hook and a series 

 of fine marginal teeth above and a series of one large and several fine 

 teeth below the median hook. The lateral scutes on the caudal ped- 

 uncle have a more enlarged median hook, and the fine marginal teeth 

 fewer, or none. No plates on dorsal or ventral surface. Distance of 

 the dorsal spine from the snout 2^ in the length. Dorsal spine 

 slightly curved, its anterior margin with rather long and fine teeth to 

 near the tip, its posterior margin with short, wide-set teeth. Space 

 between dorsal and adipose fins 3^ in the length. Adipose fin as 

 high as long. Caudal scarcely emarginate, the lower lobe much wider 

 and somewhat longer than the upper. Anal fin as high as long, 

 rounded. Ventrals not reaching anal by yi their length. Pectoral 

 spine strong, longer than the dorsal spine, reaching to the second 

 third of the dorsal fins ; both margins serrate, both surfaces striate. 

 Color light brown ; silvery below lateral scutes ; anal and pectoral 

 fins peppered with dark. 



Head 3^ ; depth 2f ; lat.l.29; D.I, 6; A. 12 ; V. 7; P.I, 8. 



19. Auchenipterus nigripinnis Boulenger. Bagre Sapo. 

 Two specimens, Corumba and Puerto Max (353). 



20. Trachycorystes striatiilus (Steindachner). 



Two specimens. Tributary of Rio Pilcomayo (444). 



Pygidiid^e. 

 HomodicEtus Eigenmann and Ward, gen. nov. 

 Type : Homodiatus anisitsi Eigenmann and Ward. 

 Dorsal behind the ventrals ; no teeth on the vomer j gill-membrane 



