Dr. 11. Phili[)pi o?i the River-Fishes of Chili. 431 



The number of the anal rays is not given. Most of the cha- 

 racters given by Leybjld are generic ones, and belong to all the 

 species of Arius ; that, however, of the spine of the pectoral fin 

 being unserrated (for this is what is actually meant by the ex- 

 pression "pectoralibusundique inermibus — pectorales sin diente 

 alguno ^') would be a very peculiar one ; but beyond a doubt 

 this rests on an error. In the living or freshly killed specimens 

 the teeth on the hinder edge of the pectoral spine are not 

 apparent; but in the same specimens after a longer immersion 

 in spirit they become even more conspicuous than in any other 

 species. Nevertheless I look upon A. carcharias as a good and 

 easily definable species ; for, in the first place, it has only eight 

 rays in the anal fin, while A. papillosus has twelve ; and in the 

 second, the lips, chin, gill-membranes, and isthmus are thickly 

 covered or, so to speak, paved with large, broad, flat warts, and 

 not with small papillae '^qui rendent la peau comme saigneuse/' 



4. Arius villosus, Ph. 



On examining the specimens of Arius in the Museum on the 

 occasion of Herr Leybokrs present of A. carcharias to the col- 

 lection, I found another species (differing from both A. papillosus 

 and A. carcharias), which I named A. villosus, but, being other- 

 wise occupied, Lad not then the leisure to describe. It is 

 characterized by having almost the entire body thickly covered 

 with a minute down, almost densely pubescent. The under 

 surface of the head has the large warts of A. carcharias ; but 

 they are not so close together, and project more. The adipose 

 is very large, and reaches, when laid back, to the fleshy borders 

 of the caudal. (These fleshy borders are, by the by, entirely 

 forgotten in Cuvier and Valenciennes^s figure of ^. papillosus.) 

 The entire fish measures 186 millim. in length, and the adipose 

 fin is 31 millim. long and 8 millim. high. The membrane 

 separating the nostrils appears to me larger than in other 

 species, and forms a valvular covering to the upper nasal 

 aperture, surrounding the lower mostly as a projecting lamellar 

 border. The colour is a very pale reddish brown, passing into 

 ])ure white on the belly. The number of the fin-rays is as 

 follows:— D. 17; A. 11; C. 18; P. 18; V. G. 



The rays of the caudal are difficult to count, by reason of the 

 thick membranous covering which hides them ; I do not think, 

 however, that there are twenty of them. The rays of ihe anal 

 fin aie as h)ng as those of the first dorsal. The ])alatinc teeth 

 are as large and as ])ointed as those of the maxillary, and form 

 two slightly diverging oval patches. 



5. Arius sqvalus, Ph. 



The fore part of the body is thickly covered with minute 



