CHAP. XV. 



THE ANCEUS 



299 



bottom of the sea, but it swims with great rapidity, 

 propelling itself forward by the quick motions of a 

 series of ciliated fins placed beneath the tail. The 

 Anceus, in its young state, is parasitical, and is 

 furnished with a sharp process at the apex of the 

 anterior lip, to form a strong lanceolate organ, with 

 which the animal cuts its way through the skin of the 



LARVA. 



PRANIZA EDWARDII. 



fish on which it preys. It was at first thought that 

 Praniza Edwardii was a female, and that the male 

 had not yet been discovered. On seeing this stated 

 in the number of the Sessile-eyed Crustacea in which 

 the Praniza was noticed, Edward wrote the following 

 letter to Mr. Spence Bate :- 



" My dear Sir Some considerable time ago I sent you 

 amongst other things, what I believed to be two distinct 



