Dr. 11, Philippi on the River-Fishes of Chili, 433 



The fore part of the body is, as in most of the species, beset 

 with minute papillae, the hinder portion being quite smooth. 

 The total length is 201 millim. ; length of the head 34, its 

 breadth the same, and its greatest height 20 millim. ; the 

 greatest height of the body at the middle of the dorsal fin is 

 32 millim.; tail 27 millim. high and IH miUim. in thickness. 

 Number of the fin-rays :— D. 1 . 7; A. 11 ; C. 18-20 ; P. 1. 9 ; 

 V. 6. The adipose is 26 millim. long and 7 millim. high. 

 Coloration uniform grey, darker on the upper parts ; the lower 

 surface lighter. 



Note, — All the species of Arim have in the axilla, above the 

 pectoral fin, and immediately under the end of the os coracoi- 

 deum, two apertures, one behind the other, the anterior one being 

 the smaller. 



8. Trichomycterus areolatuSj Cuv. & Val.; Guich.in Gay,ii.p.309. 



Easily distinguished from the other species by the singular 

 folded appearance of the skin on the under surface of the head. 



9. Trichomycterus maculatus, Cuv. & Val. U. S. N. A. Exp. 



p. 243, tab. xxxiv. f. 1-3. 

 Guichenot has not given the number of the fin-rays ; Cuv. 

 and Val. give J). 15, A. 9 ; Girard, however, has D. 13, A. 8. 



10. Trichomycterus mar mar atus J Ph. 

 Blackish-grey, varied with numerous small black spots 

 resembling those of Tr. punctatus ; the ground-colour of the 

 tail is more of a brownish yellow ; belly white and spotless, as 

 are also the pectoral, ventral, and anal fins ; dorsal and caudal 

 blackish. Its shape is slenderer than that of Tr. punctatus, Cuv. 

 and Val., as the admeasurements will show ; length of the largest 

 of the four specimens at hand 119 millim.; length from tip of 

 snout to commencement of dorsal 55 millim. ; length of dorsal 

 10 millim. ; distance between end of dorsal and end of caudal 

 30 millim. ; height of dorsal 7^ millim. ; greatest height of 

 body 11 millim. The lips are smooth, without papillae; the 

 maxillary barbels are as long as those of the nasal region, 

 shorter than the head, and black. The under surface of the 

 head shows no areola?. I find the fin-fornnila to be as 

 follows :— D. 10 ; A. G ; C. about 14 ; P. 8 ; V. 6. This spe- 

 cies is therefore easily distinguished from Tr. areolatus by the 

 condition of the skin of the inferior surface of the head, and the 

 number of the rays in the dorsal and anal fins ; from Tr. macu- 

 latus by the last-mentioned character and its blackish colouring. 



11. Trichomycterus tiyriniis, Ph. 



This species is easily discerned at the first glance by its 

 coloration. It shows on a white ground numerous reddish- 



