Dr. R. Pliilippi on the River -Fishes of Chili. 429 



Eels seem not to occur in the fresh waters of Chili ; but the 

 sea possesses a true Conger, which the fishermen call AnguiUa 

 negra, and to which I have applied the name Conger chilensis. 

 The Congrio of the Chilian fishermen is no Malacopterygian ; 

 I have described it under the appellation of Gemjpterus 

 nigricans J and the AnguiUa blanca is Bdellostoma 'pohjtrema, 

 Girard. 



According to Gay the order Cyclostomata is entirely un- 

 represented; it is now, however, some time since a species, 

 Bdellostoma Dombei/i, was made known through Dombey 

 as occurring in the Chilian seas; and Girard has added a second, 

 Bd. j)olytrema ] while Gray mentions a Velasia chilensis (^vo- 

 bably my Thijsanochilus valdivianus) from the fresh waters. I 

 have described two species of Petromyzon, P. Foncki and 

 P. acutidens, as also several early stages of Ammocostes and 

 Chilopterum ; whence it would seem probable that more species 

 of Petromyzon will yet be afforded. 



I will now enter into a short description of some of the river- 

 fishes which appear to me to be new. 



1. Percilia gracilis J Ph. 

 Corpora angusto; dentibus obtusis, cylindricis, subtruncatls. 



From the waters of Peine in Santiago. 



The entire length of the fish is 60 millim., its greatest height 

 only 111 millim., its thickness 7 millim. The head from the 

 snout to the point of the gill-cover is 14 millim. long. With 

 regard to the general form of the fish, we may notice the regular 

 and rather strong curve of the head from the shoulder to the 

 snout; the back and belly present regular, equable and gradual 

 curves. The nasal apertures are situated each in a rather long 

 depression, bounded by a sharp ridge ; and the sjmce between 

 the two ridges is also depressed. The eyes are 4 millim. in 

 diameter. The forehead and shoulder are scaleless ; the scales 

 of the pncoperculum and of the operculum are smaller than 

 those of the body, which are large, rough, and ciliated. 



The upper surface and dorsal fin, as also the caudal, are grey; 

 the ventral surface and anal fins whitish; the chest and ventral 

 fins bright citron-yellow. Lateral line bent suddenly beneath 

 the middle of the second dorsal fin. The numbers of the fin-rays 

 are as follows;— I. D. 7; II. D. 10; A. 3-7; P. 15; V. 6; C. 

 about 18. 



2. Arius papillosus, 



Cuvier and Valenciennes have described and figured (vol. xy. 

 p. 118, t. 431) under this name a fish said by Gay to be from 

 Chili ; and under the same name we find a fish described by 

 Guichenot in Gay, and figured by him (vol. ii. p. 305, and t. 5 bis, 



