280 MEMOIRS OF THE CARNEGIE MUSEUM. 



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

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

 opercle unarmed. 



This genus resembles members of the Pimelodinec 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 Siluridce. 



Habitat— Chile. 



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

 Native name "Bagre." 



Trichomycterus inermis Guichenot, in Gay, Hist. Chil. Zool., II, 1848, p. 312; 



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

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

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

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

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

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

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

 Delfin, Gatalogo de los Peces de Ghile, 1901, p. 29 (Central Provinces of 

 Ghile); 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, /. c, p. 716. 

 Habitat. — Fresh-waters of central Ghile. 



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 brown, mottled with darker; a series of about five fight areas 

 along the lateral line; fins speckled. 



Genus II. Scleronema 14 Eigenmann. (Plate XXXVI.) 



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

 Type. — Scleronema opereulatum sp. now 

 Allied to Pygidium. 

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



" <n<X7)p<$5= hard. »?/«*, t6= thread, in allusion to the hard base of the maxillary barbel. 



