ii7 



HELIX ASPERSA m. SCALARIFORME Taylor. 



By J. R. B. MASEFIELD. 



(Read before the Society, March i?th, 1913). 



In the ' Queen ' newspaper for the 30th November last was a 

 photograph of a hving specimen of this variety of mollusc which had 

 been deposited at the London Zoo from Haverfordwest, Pembrokeshire. 

 The whorls are absolutely separated in the form of an elongated 

 cornucopia and consequently there is no columella. With the 

 description of this shell it was stated that the keeper found this 

 mollusc " walking abroad without its shell, whereupon it was promptly 

 seized and again safely housed, since when it has not broken bounds." 

 I communicated with I\Ir. R. I. Pocock, the superintendent of the 

 Zoo, as to this somewhat startling announcement, and he very kindly 

 allowed me to examine this snail last month. I found it crawling up 

 the glass side of its case, and 1 noticed on handling the shell that the 

 two top whorls were transparent, and the body of the mollusc extended 

 only a little beyond the large bottom whorl. Besides this, the apex 

 of the shell appeared to have received injury sometime, and was 

 slightly decollated. On placing the animal in tepid water for a short 

 time it soon crawled out over my hand. When extended to its full 

 length, and by using a very slight pull, the whole body came absolutely 

 out of its shell and crawled about in an apparently happy condition. 

 We afterwards replaced the mollusc in its shell. I take it that from 

 some cause the retractor muscles had become atrophied or had never 

 developed at all in consequence of there being no columella. Mr. 

 J. W. Taylor tells me that he has known similar instances before, and 

 in \ki^ Journal of Conchology, vol. iv., p. loi, he states that an account 

 is given in the " Journal de Conchyliologie " of a specimen of this 

 form, which was entirely detached from its shell and continued healthy 

 and active. In vol. ix. of the Journal of Conchology, p. 112, Mr. 

 A. G. Stubbs gives another instance in the case of Linincea peregra, 

 attributing the occurrence to disease, and at pp. 164 and 217 of the 

 same volume other instances are given. 



