Seas lugs 



75 



Gizzard-plates 

 of Acera 



Soft 

 Bubble-shell 



darker tints, and broken lines of purple-brown. The 

 creature has no tentacles (hence its name, Acera, 

 without horns), and its small black eyes 

 are not conspicuous. Its gizzard is not 

 so powerful as that of the Canoe-shell, 

 but it is well provided with a number 

 of triangular horny plates for the tritu- 

 ration of its food. When alarmed it is 



said to eject a purple fluid. Like 

 Haminea it uses its foot-lobes for swim- 

 ming purposes. It occurs chiefly on our 

 southern shores and the coasts of Scotland 

 and Ireland, in from 3 to 15 fathoms, on 

 ooze and mud. 



The Lobe-shell (Fhiline aperta) has its 

 delicate, thin white shell completely 

 invested by the transparent white 

 mantle ; but though covered in this 

 way, so clear is the mantle that both 

 shell and gizzard may be seen through 

 it. This pellucid covering is dotted 

 with opaque white specks wdiich give 

 a very close resemblance to certain 

 of the Compound Ascidians. This 

 likeness, no doubt, serves its purpose 

 in avoiding destruction.' It is said to 

 be capable of swimming by using its 

 side lobes. It is coumion on sandy shores from 

 extreme low water to about 50 fathoms, all round 

 these islands. There are seven other native species, 

 of which the names will be found in the Appendix ; 

 among them is the Dotted Lobe-shell (P. j^u'iictata), 

 a minute species only about an eighth of an inch in 



Lobe-shell 



