161 



by the former mark. A large specimen of this last named 

 species was taken in the Mount's bay, and is well pre- 

 served in the museum of the Society for Natural History 

 at Penzance. From an examination of this I derive the 

 following description: length three feet two and a half 

 inches; extreme breadth two feet three inches; the margin 

 much rounded, and expanding much more than in either of 

 Mr. Yarrell's figures. Mouth narrow, and apparently feeble, 

 the under jaw curved forward in the shape of a horse shoe ; 

 teeth small and sharp; temporal spiracles with an even 

 continuous border. Colour of the upper surface deep brown, 

 the skin smooth, sprinkled with small shot-like spots having 

 some approach to regularity of distribution. The posterior 

 lobe of the body has a regular fin with nineteen rays, of 

 which three at the two extremities single, the others double. 

 Oi the two dorsal fins the anterior is partly on the lower lobe 

 of the body, two inches and a half long, two inches and 

 three quarters high; the distance between them two inches 

 and three eighths. Second dorsal one inch and a half long, 

 two inches high ; from which to the caudal fin, two inches 

 and a half. Eyes small, two inches and three eighths apart. 



Mr. Dillwyn ( History of Swansea, p. 61,) describes a spe- 

 cimen clearly similar to the above, that measured in length 

 forty-two inches, thirty inches wide, and weighed forty-three 

 and a half pounds, and an observation of that gentleman on his 

 specimen before and after it was set up tor preservation, will 

 explain much of the discrepancy observed in the descriptions 

 ami figures of these fishes given by different authors. With 

 the utmost care that was employed, the specimen, between 

 the time of its death and preservation was found to have 

 stretched from forty-two to forty-nine inches in length, and 

 to have diminished in breadth from thirty inches, to twenty- 

 four, a circumstance which will explain the dispropor- 

 tionate dimensions of Risso's figures, and the want of ex- 

 pansion in even the British engravings. The specimen at 

 Penzance had been measured previously to setting up; and 

 it is now fixed on a board suited to its natural figure. 



SQUALID^G. SHARKS. 



HAMMERHEAD. Squalus zygcena. Linnaeus. Risso, 

 Ichthyologie, p. 34. Zygaeua malleus, Jenyns' Man., 

 p. 507. Yarrell's Br. F., vol. 2, p. 504. 



More than a single specimen of this curious and voracious 

 Shark, have been taken in Cornwall ; but the only one pre- 

 served, is in a dissected state in the museum of Natural 

 History at Penzance. 



