ANGLER FISHES — GILL. 



577 



varies with the body; the mouth ranges from nearly horizontal to 

 vertical and from moderate to great extent; the branchial apertures 

 are behind or below the axils of the pectorals; the pectorals have 

 abbreviated pseudobrachia with three actinosts and are not at all 

 geniculate; the first dorsal is represented by a single ray advanced 

 forward over the snout and "baited" with a ''lure" or "bait;" in 

 some a post cephalic spine or caruncle is developed ; the second dorsal 

 and anal are generally very short, but in some more extended and 

 multiradiate; the caudal is quite uniform in composition, having gen- 



Fiu. 11. — Skeleton of a himautolopbiue Ceratiid (HiDiantolophun rcinhurdti) . 



Liitken. 



After 



erally eight or nine rays, four or six medium rays forked, and one or 

 two upper and one to three lower simple rays. 



Much diversity is manifest in this group, extending to the com- 

 pression of the head and body, the extent and direction of the mouth, 

 the development of the dorsal and anal fins, and the modification of 

 the rostral spine. Most have the mouth moderate and the dorsal and 

 anal pauciradiate (D. 4, A, 4), but a few {Melanocetlnes) have a very 

 deeply cleft mouth and pluriradiate fins (D. 14). The skin is gen- 

 erally naked, but in some {Himantolophines and .^ga'oniehfhyines) 

 is beset with scattered tubercular plates. Almost all have the head 

 compressed, but in one group {.^gceonichthyines) it is depressed. 



