40 THE DISCOBOLI. 



LIPAROPSIDiE. 



The deterioration of the first or spinous dorsal, seen in the Lump-fish, 

 has apparently proceeded so far in the Liparopsidae as to cause the dis- 

 appearance of that fin. Each of the two genera in the fiimily has but a 

 single dorsal, the posterior. On one genus the fin is short and situated 

 near the caudal, on the other the fin begins near the middle of the back 

 and extends nearly to the origin of the caudal. The genera are further 

 distinguished by dorsal tubercles in one case, and by a naked skin in the 

 other. The shape is somewhat like that of the Diodons, bulky, thick) 

 broad, and longer forward, in the section containing the visceral cavity, 

 and short and greatly reduced in size behind it. The head is short, broad, 

 and thick, the snout short and blunt, the mouth terminal, the teeth are 

 subconical, the eyes lateral, the branchiostegal rays six in number, the 

 gill openings narrow, the gills three and a half, the pseudobranchs small, 

 all, with disk, pectorals, and caudal, as in the Cyclopteridaj. Until recently 

 this family has been known only from the North Pacific. A short time ago 

 a second species of Cyclop terich thy s was named by Vaillant from a sketch 

 of a fish taken in the Straits of Magellan, which would extend the distribu- 

 tion to the Antarctic regions. 



PACE 



Dorsal short ; no tubercles, CYCLOPTERicnTiiTS, 40 



Dorsal elongate ; tubercles present, ' Lipakops, 42 



CYCLOPTERICHTHYS. 



Form resembling that of the Diodons, massive anteriorly, thick and 

 rounded to the dorsal, thence compressed to the caudal. Head broad, short, 

 moderately arched, sides steep. Skin thick, soft, naked. Gills three and 

 one half. Gill opening a narrow slit, above the pectoral. Gill membranes 

 united, joined to the isthmus. Pseudobranchiae. Teeth simple, hooked, 

 in few series. Orbital ring connected with the preoperculum. Dorsal 

 single, posterior. Ventrals united, forming an adhesive organ. Stein- 

 dachner, 1881, established the genus upon his species C. glaber, afterward 

 identified with C. ventricosus of Pallas. 



