288 THYONES. 



HOLOTHURIA DJE. THYONES. 



PORTLOCJTS THYONE. 

 Thyone PortlocMi. Forbes. 



Specific Character. — Body cylindrical, corrugated, white ; suckers numerous, 

 large ; tentacula frondose, purple. 



The Thyone PortlocJcii is a large species, measuring five 

 inches in length, and connects by its form and general 

 aspect the genus Thyone with Cucumaria. The body is 

 white, and is covered with a strong smooth coriaceous in- 

 tegument, over which the strong white suckers are some- 

 what irregularly scattered. On the five angles they are 

 most numerous and rudely arranged in rows. The ten- 

 tacula are ten in number, large, frondose, and purple. The 

 internal structure of the animal presents a large and strong 

 dental apparatus, numerous genital and respiratory tubes, 

 and one pyriform sac. This handsome species was kindly 

 communicated to me by Captain Portlock, to whom I have 

 dedicated it, and by whom it was discovered in Belfast 

 Bay, in the course of the Ordnance investigations in the 

 North of Ireland. 



