280 MEMOIRS OF THE CARNEGIE MUSEUM. 



serrae on its posterior margin ; anal short ; fontanel extending to the base of the 

 occipital process, with a bridge over posterior margin of the eye; opercleand inter- 

 opercle unarmed. 



This genus resembles members of the Pimdodiruc more than the other species 

 of the family, and is probably nearer the primitive stock of the family than the 

 following more highly specialized genera, if it is not a member of the Siluridcc. 



Hahitat.— Chile. 



1. Nematogenys inermis ((kiichenot). (Plate XLII, figs. 1, 2.) 

 Native name "Bagre." 



TrirJwmycterus inermis Guichenot, in Gay, Hist. Ghil. Zool., II, 1848, p. 312; 



1854, pi. IX, fig. 2 (Chile). 

 Nematogenys inermis Girard, Proc. Acad. Nat. 8ci. Phila., 1854, p. 198; U. S. Nav. 

 & Astron. Exped., 1855, p. 240, pi. XXXII (Rio Maypu near Santiago); 

 Gunther, Cat. Fish. Brit. Mus., V, 1864, p. 272; Philippi, Mb. Ak. Wiss., 

 Berlin, 1866, p. 716; Eigenmann & Eigenmann, Proc. Cal. Acad. Nat. Sci., 

 (2), 11, 1889, p. 50 (Curico; Santiago); Occasional Papers Cal. Acad. Sci., I, 

 1890, p. 323 (Curico; Santiago); Proc. U. S. Nat. Mus., XIV, 1890, p. 36; 

 Delfin, Catalogo de los Peces de Chile, 1901, p. 29 (Central Provinces of 

 Chile); Eigenmann, Reports Princeton Univ. Exped. Patagonia, III, 1909, 

 p. 246, pi. XXXI, fig. 2; 1910, p. 398, pi. XXXII, fig. 2. 

 Nematogenys nigricans Philippi, Mb. Ak. Wiss., Berlin, 1866, p. 716. 

 Nematogenys pallidus Philippi, I. c, p. 716. 

 Habitat. — Fresh-waters of central Chile. 



Head 3.8-4.33; depth 6-7; D. 10; A. 11; P. I, 8; Br. 11 12; eye small, superior; 

 interocular little less than snout; caudal peduncle about as deep as body; origin of 

 dorsal one-fifth nearer snout than to base of middle caudal rays in specimens 120 

 mm. long, one-fifth nearer caudal than snout in specimens 260 mm. long; origin of 

 anal much behind the last dorsal ray ; fins all rounded ; caudal with numerous acces- 

 sory rays. Light l:)rown, mottled with darker; a series of about five light areas 

 along the lateral line; fins speckled. 



Genus II. Scleronema'* Eigenmann. (Plate XXXVI.) 



Scleronema Eigenmann, Proc. Am. Philos. Soc, LVI, Jan., 1918, p. 691. 

 Type. — Scleronema operculatum sp. nov. 

 Allied to Pygidium. 

 Ventrals nearer snout tlian to caudal; outer pectoral rays shortest, without a 



" aK\r,pU= hard, pr,y.a, t6 = MiiCMil, ill alliisidu to the hnrd base of the maxillary barbel. 



