370 MEMOIRS OF THE CARNEGIE MUSEUM. 



Body compressed, extremely slender. Head broad, the snout rounded; mouth 

 broad, inferior. Opercle long and slender, terminating in three spines, trident- 

 shaped. Pre-opercle with similar but smaller spines. Barbels minute, scarcely 

 evident. Distance of origin of dorsal fin from extremity of caudal 3 in the length ; 

 origin of anal fin from extremity of caudal 2.5 in the length. Anal rays rapidly 

 decreasing in height backward, the last ray about under the last ray of the dorsal. 

 Caudal rounded, without accessory rays. 



Yellowish; posterior half of the caudal fin dusky; a series of black spots along 

 the base of the anal. 



2. Tridens brevis Eigenmann & Eigenmann. 



Tridens brevis Eigenmann & Eigenmann, Proc. Cal. Acad. Sci. (2), II, 1889, p. 54 



(Tabatinga); Occasional Papers Cal. Acad. Sci., I, 1890, p. 340; Proc. U. S. 



Nat, Mus., XIV, 1891, p. 37; Eigenmann, Reports Princeton Univ. Exped. 



Patagonia, III, 1910, p. 401. 



Habitat. — Tabatinga. 



Known from the type, 21 mm. long, in the Museum of Comparative Zoology. 

 A recent search for it has failed to locate it. 



Head G; depth 8; D. 9; A. 22. 



Body short and deep. Head as broad as long; mouth broad, inferior. Opercle 

 with a bunch of six or more spines; pre-opercle with a smaller bunch of spines. 

 Barbels well developed, the outer one extending to the base of the pectoral, the 

 inner to the gill-opening. Eye large, nearer end of opercle than tip of snout. Dis- 

 tance of origin of dorsal from tip of caudal little more than two in the length. Anal 

 inserted very little in front of the dorsal and extending some distance beyond it, 

 its rays decreasing in height toward the caudal. Origin of anal from extremity of 

 caudal less than 2 in the length. First pectoral ray greatly produced. Caudal 

 emarginate. 



Yellowish; blackish dots along the bases of the fins; a series of blackish dots 

 along the middle line of the sides; similar spots on the back. Head with brown dots. 



Genus XVIII. Miuroglanis 42 Eigenmann & Eigenmann. (Plate XXXIX.) 



Miuroglanis Eigenmann & Eigenmann, Proc. Cal. Acad. Sci. (2), II, 1889, p. 55. 



Type. — Miuroglanis platycephalus Eigenmann & Eigenmann. 



Anal long, with fifteen rays, its origin in front of that of the dorsal; no nasal or 

 mental barbel; two barbels at- angle of mouth; head greatly depressed, eye lateral, 



4 - udovpm = curtailed; 7Xa« s , 6 = a catfish. 



