TIIYONE PAPILLOSA. 



183 



family may be understood from the annexed figure, 

 which represents Thyone papillosa, a species found on 

 various parts of the coast. It differs from other animals 

 of the family chiefly by having its sucking-feet scat- 

 tered in an irregular manner over the whole surface, 

 instead of being confined to five rows along the angles 

 of the body. In other respects it resembles most of its 

 kindred. Its length is about three inches, but it can 

 at pleasure extend and contract considerably. The 

 colour is a dusky brownish white, sometimes varied with 

 spots. The tentacula, commonly whitish, are ten in 

 number, pinnate, and capable of being much expanded, 

 or wholly retracted within the orifice of the mouth. 

 In captivity it is not always easy to persuade it to put 

 forth these delicate organs to their full extent, but a 

 bath of clean water will often put it into good-humour. 

 We have already noticed the self-destruction of some 



