102 BULLETIN 150, UNITED STATES NATIONAL MUSEUM 



The specific coloration appears to be quite constant and of consider- 

 able taxonomic importance. We have hardly enough material to 

 draw any definite conclusions concerning the color variation within the 

 species. A few examples will suffice to indicate both our lack of knowl- 

 edge concerning the variability of coloration in these fishes and the 

 possible importance of the color in distinguishing species. C. spectrum 

 and C. gilherti resemble each other closely and formerly have been con- 

 fused. Their coloration differs, however, for in C. spectrum the stom- 

 ach is always white and in C. gilherti blacldsh. The difference in the 

 color of the stomach is supplemented by anatomical differences which 

 have formerly been overlooked. C. spectrum and C. melanurus are 

 closely related species. The former difTers from the latter in having 

 less pigment in the mouth, gill cavity, peritoneum, and the posterior 

 part of the body. The two species differ also in distribution; they 

 inhabit neighboring regions. In some of the specimens of C. melanu- 

 rus the peritoneum has little more pigment than is typical of the 

 species C. spectrum. C. cypselurus varies somewhat in coloration. 

 The posterior part of the body is always black, but the anterior part 

 varies from wliitish to purplish black. C. entomelas and C. entargyreus 

 were thought at first to differ solely in the amount of pigment in the 

 peritoneum, but further study brought to light other differences. 

 These few examples indicate that whenever we find two specimens 

 differing in coloration it is possible that they represent different 

 species and that other differences should be searched for. 



Habits. — Our knowledge concerning the habits of these fishes 

 must necessarily be limited. The dredging records indicate in most 

 cases, nothing but the depth at which the species exist and the kind 

 of bottom they inhabit. The structure of the body, from analogy, 

 indicates in some cases what the habits may be. The species taken 

 in intermediate hauls are of course free-swimming forms. The 

 majority of the species of the genus have the body compressed and 

 deepened and probably seldom rest upon the bottom. The rays of 

 the lower pectoral lobe are elongate in a number of species and 

 possibly are used as feelers. C. pycnosoma and the few other species 

 with depressed bodies probably come to rest upon the bottom as do 

 the species of Liparis. C. rJiodomelas, judging from the contents of 

 the stomach and the character of the teeth, feeds mainly upon 

 Ophiurians and must remain in close proximity to the bottom. The 

 genus is represented on all kinds of ooze and rock bottom. 



Summary. — In order to present a guide to the study of the specific 

 characters of these fishes the following outlines are given. The first 

 list suggests the characters which have been found to be the most 

 useful in distinguishing the species. The second list involves those 

 characters which were studied but not used to any extent. With 



