ANGLER FISHES— GILL. 



575 



mouth is cleft very obliquely and in some even vertically; the bran- 

 chial apertures are in or behind the lower axis of the pectoral fins, 

 these fins themselves are well developed and so articulated with the 

 pseudobrachia or false arms as to form elbowlike joints, the fins 

 being dirigible downward and forward; the pseudobrachia are 

 formed by actinosts moderately elongated and only reduced to three 

 on each side ; the ventrals are of moderate size and provided with five 

 (or four) rays, and the spinous dorsal is variously developed, mostly 

 Avith three spines, but represented by at least a rostral tentaclelike 

 ray. These characters are associated with various osteological j^e- 

 culiarities, the most notable being the development of upraised haemal 

 spines to most of the abdominal vertebra?. 



Fig. 9. — Pteiupluync histrio. After Jordan and Sindo. 



As so limited, the family embraces a dozen or more genera which 

 represent three groups of supergeneric value, the subfamilies A7iten- 

 narmue, Brachionichthyirut, and Chaunacina\ 



The two most generalized of the three groups have the body and 

 head notably compressed, and the first dorsal fin is represented by 

 three raj^s, the foremost of which is generally reduced to the form of 

 a rostral tentacle, while the second and third are robust spines; the 

 soft dorsal is well developed. The two groups are in their turn dis- 

 tinguished by well-marked characteristics. 



The least specialized species have the body oblong claviform, the 

 mouth is comparatively small, the palate unarmed, the pelvic bones 

 are short, and the twenty or thirty dorsal rays are approximated 



