CDRIOnS EXAMPLES, 141 



have surrounded the aperture, and meet each other on 

 the outer lip. Here the meeting edges unite by 

 mutual adhesion, and seem to grow together, yet the 

 suture is always distinctly visible, both by a slight 

 depression, and by a pale line which assumes a 

 zigzag form, owing to the terminations of the body- 

 strise fitting into the interspaces of the opposite ones. 



What is curious in the case is the instinct which 

 makes the Adanisia select a shell as its constant 

 support, and the association with it of a Hermit Crab 

 as the co-tenant of the same shell. This association 

 is I think constant ; for though the dredge does 

 occasionally bring up shells invested by the Adamsia, 

 which are empty, yet I incline to believe that these 

 shells have been recently vacated by the tenant 

 Crabs, and not that they have never been so occu- 

 pied at all. 



That the above is the correct explanation is evident 

 from specimens in various stages of development. 

 There is in my possession, while writing this note, an 

 Adamsia, adhering to a Whelk, of which the lateral 

 lobes, though projected around the edges of the mouth 

 of the shell, have not yet met each other on the outer 

 lip, but are separated by a space of a quarter of an inch. 

 And my friend Mr. Thompson, whose opportunities 

 for studying the marine animals of Dorsetshire, have 

 been most zealously improved, has just showed me a 

 very young specimen, not larger than a silver three- 

 pence, in which the side lobes were not in the least 

 developed. This specimen had selected a land shell 

 as its support, a not quite adult Garden Snail {Helix 

 aspersaj, within which a Pagurus Prideauxii had 



