486 MITCHILL ON THE FISHES OF NEW-YORK. 



6. Basking Shark. (Squalus maximusJ) Of a brownish lead colour 

 above, whitish below, and small conic subulate very numerous teeth. 



A shark of huge size, taken in considerable numbers near Province 

 Town, Cape Cod, for the oil which his liver affords. 



He is remarkable for having something within his mouth resembling 

 the horny substance called whale-bone, which has led some persons t# 

 call him the bone-shark. 



7. Dog-fish. (Squalus canis.) With small mouth, blunt teeth, the 

 lower jaw shutting within the upper, and a tail almost straight. 



Length, when full grown, four feet and more. 



Colour leaden or ashen ; rather dark on the snout and back, but pale 

 on the sides, and white upon the belly. Neither spots, stripes, nor 

 spines, on any part. Sometimes the fins are tinged with red ; and the 

 dorsals and caudal fringed behind with white. 



Opening of the eye-lids oblong and horizontal. A nictitating mem- 

 brane within the lower lid, capable of rising and excluding the light. 

 Iris greenish yellow. Situation of the eyes, on the upper side of the 

 head, half an inch or more from the edge of the snout. Immediately 

 behind the eye, a hole or orifice, big enough to admit the end of a large 

 probe. 



Nostrils beneath the snout, capacious, with membranous covers and 

 partitions. 



Mouth small for a shark. Teeth blunt, and disposed after the man- 

 ner of a file. The extremity of the lower jaw is toothed, and shuts 

 within the teeth of the upper. Tongue white and scarcely rough. 



Snout broad and blunt, but tapering rather toward a point, forward. 



Two dorsal fins, of a somewhat triangular figure. The two ventrals, 

 with their appendages, conceal the vent. Two anal fins, the foremost of 

 which corresponds to the second dorsal, and the second is far back under 

 the tail. 



