1818.3 OF THE UNITED STATES. 43^ 



Inhabits dog fish, (SquaUis Canis? Mitchill) 



Cabinet oi the Academy. 



Length one fifth of an inch. 



Body longitudinally oblong-quadrate; thorax trans- 

 verse-quadrate,somewhat narrowed before, emarginate be- 

 tween the antennas, middle of the base rectilinear and fus- 

 cous, angles projected backward and rounded at tips; an- 

 tennce very short; anterior feet formed for suction, at tip 

 oval or subreniform,and placed obliquely; scales ^ionr sub- 

 equal ones in a transverse line at the base of the abdomen, 

 each transverse and rounded at tip, and two larger ones 

 originating beneath the preceding, slightly dentate at tip 

 and not concealing one half of the abdomen; abdomen 

 quadrate, as wide as the thorax but rather longer, posterior 

 edge with a central sinus and lateral one each side, poste- 

 rior angles acute; oviducts filiform. 



Very commonly occur in considerable numbers on 

 this species of Squalus, attaching themselves more par- 

 ticularly about the bases of the flns. They are by no 

 means so active as the Caligus piscinusyvAiizh also occurs 

 in plenty on the Cod-Hsh of our coast. 



G^/zw^ BINOCULUS. Geof. 



Body suboval; thorax large; eyes two; abdomen of 

 three, or four transverse segments; tail setaceous at tip. 



SPECIES. 



B. caudatus^. Body sub ovate; thorax semioval or pa- 

 rabolic, posterior edge retuse for the reception of the ab- 

 domen, no dorsal, or transverse anterior line; antenna ex- 

 teriores laterally and horizontally extended, more than half 



