303 



In order to avoid all possible misunderstanding with regard to 

 C. asper, I cannot but make a new generic name. It has a 

 closer affinity to Cottus proper than to any genera of the marine 

 tribe [Acantlio cottus^ Trachidermis^ Podahrus.) In retaining for 

 it the name of Centridermichthi/s, its relationship would be 

 mistaken, as we now have that name as a synonym among Tra- 

 chidermis. Moreover, C. asper was never intended to be its 

 true type. 



For a long time I used in my notes the name of Cottopsis as 

 most appropriate for that species, and I now introduce it in the 

 nomenclature, and recommend it to the attention of Ichthyolo- 

 gists. The characters of this genus will be better understood if 

 we bear in mind that the fresh water Cotti, as a tribe, differ from 

 the marine species, as I have shown on a former occasion.* 

 Now, it differs from Cottus proper by its teeth on the palatine 

 bones, and the roughness of its skin ; also by its larger size ; — 

 from Trachidermis by its smooth head, its first dorsal fin, and 

 the shape of its mouth, which resemble the head, first dorsal fin, 

 and mouth, of Cottus proper ; — from Acantho cottus also by its 

 smooth head, its first dorsal fin, and its mouth, and especially by 

 the presence of teeth on the palatine bones, and a rough skin. 



There is among these genera a strange combination of a few 

 characters, which are found scattered here and there, and com- 

 bined in such a manner that two out of three will be present in 

 one place, and two others in another. 



Cottopsis asper Grd. — Cottus asper Rich. Faun. Eor. Amer. 

 III. 1836, add. pp. 295, 313, PI. 95, fig. \.— Trachidermis 

 RicJiardsoui Heck. Ann. Wien. Mus. ii. 1837, p. 162. 

 Centridermiclithys asper Rich. Ichth. of the Voy. of the 

 Sulphur, 1844, p. 76. River Oregon ; — Lewis & Clarke. 

 (Richardson.) 



The voyage of the Samarang has made us acquainted with 

 another genus of this family, which shows still more how eco- 

 nomical nature has been in the distribution of the generic char- 

 acters. 



* See Proceedings, Vol. III. p. 183. 



