284 



PROCEEDINGS OF THE NA TIONAL MUSEUM. 



VOL. XXVII. 



2; upper proopeicular .spine 6f; pectoral 2; first dorsal spine if; 

 third dorsal s])ine 3f, longest dorsal rays 3^; longest anal rays 3|; 

 ventral 2^; caudal 2i. 



Head long and but little depressed; the sides forming an angle with 

 the top. Body nowhere ci impressed. Postorbital part of head equal 

 to snout and twice the verticle diameter of eye. Interorbital space 

 wide and uniforndy concave. Maxillary reaching the diameter of 

 pupil beyond eye. Lo.ver jaw but slightly included; a knob devel- 

 oped at symphysis. Teeth small, conical, in rather wide bands on 

 jaws and vomer; the band strongly curved on the latter; its greatest 

 width ecpial to length of orbit. Nasal spines strong, not very sharp. 

 Ridges on each side of vertex not continuous, represented by a short 

 double spine liehind orbital spine (first digitate spine), and a longer 

 one at occiput, between which there is a rounded raised area, but 



Fig. 23. — Ainocottus ensiger. 



scarceh" a ridge. The ridge outside of this is low and uneven. The 

 highest spine on top of head is the superorbital spine, wliich is situated 

 over posterior fifth of orljit; l)ehind it are two digitate spines, ])oth 

 directed backward. Preopercular spine long, straight and sharp, 

 nearly reaching edge of opercle; below it are three spines, the upper 

 one the largest, scarcel}' a third as long as the large spine, the lower 

 one is directed forward and downward as usual, while the one between 

 is more obtuse than the others, and is directed downward and slighth' 

 backward. Opercle with a long, strong ridge ending in a spine; the 

 length of ridge and spine equal to twice the vertical diameter of 

 eye. Lower end of subopercle and upper end of interopercle each 

 with a sharp spine, their points converging and nearl}- touching; the 

 upper one pointing downward and backward, the lower one upward 

 and backward. Posttemporal spine long and sharp, ending about on 

 a vertical with preopercular spine. Humeral spine triangular and 



