eigenmann: pimelodella and typhlobagrus 255 



6762a C. M., 1, 150 mm., Caldas. Eigenmann. 



6763a-d C. M., 13596 I. U. M., 8, largest 150 mm., Barbacoas. Henn and Wilson. 



Typhlobagrus Ribeiro. 



Typhlobagrus Ribeiro, Kosmos, No. 1, January, 1907. 

 Type, Typhlobagrus kronei Ribeiro. 

 In all characters but the eyes like Pimelodella. The eyes lost. 



35. Typhlobagrus kronei Ribeiro. " Ceguinho." 



Typhlobagrus kronei Ribeiro, Kosmos, No. 1, January, 1907; Eigenmann, Re- 

 ports Princeton Univ. Exped. Patagonia, III, 1910, p. 387; Ribeiro, Fauna 

 Bras., Peixes, IV, 1912, p. 250, PI. XLII, figs. 2, 2.4 and 2B (Cavernas das 

 Areiras, Iporanga, Sao Paulo); Haseman, Ann. Carnegie Mus., VII, 1912, 

 p. 323 (Cavernas das Areiras). 

 7U3a-x C. M., 23, 74-202 mm., Caverna das Areiras, Nov. 28, 1908. Haseman. 

 Head 4-4.2; depth about 5.5; D. usually 1.6, in one case, 1.7; A. 12-15 (usu- 

 ally 14). Maxillary barbel reaching to near middle of ventrals in youngest and 

 oldest, sometimes a httle longer or a httle shorter, postmentals a little beyond 

 base of pectoral. Fontanel narrow, extending to base of occipital crest, which 

 reaches to dorsal plate, width of occipital crest nearly 4 in its length. Dorsal 

 spine half or a little more than half the length of the head, a little less than the 

 length of the pectoral spine; 8-14 moderate-sized thorns on the pectoral spine. 

 Adipose fin about 3.75 in the length, its tip extending beyond the tip of the anal; 

 caudal lobes of about equal width, the upper lobe the longer by .25 or .2 of the 

 length of the head. 



A distinct trace of a dark lateral band on some of the specimens; margin of 

 dorsal sometimes dusky. 



The region of the eye varies. No trace of an eye or optic nerve can be noticed 

 in ordinary dissections of the alcoholic material at my disposal. The skin over the 

 vanished eye is invaginated in various degrees, a distinct free orbital margin being 

 quite evident in some specimens, less distinctly so in others. They appear as 

 though the eye had been removed without greatly altering the region of the skin 

 over them. 



Ribeiro says: "Dentre os exemplares que tivemos em maos, um possue um 

 olho desenvolvido. 



"Este facto prova perfeitamente a reversao, por heranga, a um caracter de 

 sens antepassados; o orgam mede 4 millimetros no maior diametro e o peixe 150 

 millimetros. 



