THE CLOAK ANEMONE. 129 



writing this article, Mr. D. Robertson sends me accounts of 

 two in his possession, which manifested the same propensity. 

 Each first detached the two lobes from the shell, which then 

 were thickened, and apparently hollow, being much dis- 

 tended with water. The same evening, both began to 

 adhere to the side of the jar in which they were kept, by 

 their lateral lobes. Three days afterwards, the lobes were 

 " still firmly and broadly adhering to the bottom and sides 

 of the jar." Mr. Thompson, of Weymouth, has dredged 

 a specimen, which was adherent to a frond of Fucus 

 serratus. It was round, about as large as a shilling, and 

 flat, but " with the appearance of a suture down one side, 

 as though it had joined." 



Yery frequently, there is found intervening between the 

 Adamsia and the shell to which it is affixed, a film of 

 membrane, of a horny texture, somewhat brittle, of a 

 translucent dark greenish-brown colour. After death this 

 film is found adherent to the surface of the shell, from 

 which, however, it easily peels when dry. It invariably 

 extends beyond the margin of the lip, making, as it were, 

 an adventitious continuation of the shell, and following the 

 same general spiral direction. From several specimens 

 from the Frith of Clyde, for which I am indebted to the 

 kindness of Mr. D. Robertson, I have been able to learn 

 the nature and object of this membrane. In one of these 

 the shell of Trochns umbilicatus, full-grown and perfect, 

 had a great continuation of the membrane into a fictitious 

 body-whorl, as voluminous as the whole shell. In another, 

 the shell was that of Bucctnum undatum, an inch and a 

 half in height. Here the membrane was confined to a 

 small film, sub-triangular in outline, continuing the front 

 margin of the outer lip, and a similar one continuing the 

 kind margin of the same ; each the production of a lateral 

 lobe of the animal, the two not having as yet attained th« 



K 



