On the Ova of the Large Spotted Dog-fish. 



25 



how many are deposited at one time ? how long after deposition the 

 young fish bursts its prison ?" In the event of Mr. Yarrell's not know- 

 ing the ovum (which proved to be new to him likewise), he was re- 

 quested to send the drawing, &c. for Mr. Couch's opinion. With 

 respect to S. Canicula Mr. Yarrell remarked, — 



" I never remember to have observed more than one egg in each 

 oviduct ready for exclusion, but there was frequently one other in 

 each oviduct at the upper end, or about to separate from the ovarium, 

 one on each side. How long they are in passing along the oviduct, 



how often deposited, and how soon after deposition the young fish 

 leaves his cell, are points unknown to me ; but I suspect in reference 

 to gaining his liberty the young fish is rather in a hurry, for I have 

 more than once taken very small spotted sharks swimming at large 

 before the membranous bag of nutriment had been taken up into the 

 abdomen, and before the young shark had begun to take food by the 

 mouth. I will, however, send your sketch and queries to Mr. Couch." 



This gentleman replied, — 



"Polperro, Jan. 25, 1844. 



" Dear Sir, — I feel an impression that the figure of a ■ purse ' 

 which I received in your letter of the 24th of December is that of the 

 large spotted dog-fish, Scyllium Catulus. Both the British spotted 

 dog-fishes certainly spawn twice in the year, as do many other spe- 



