ox ODOSTOMIA TRUNCATULA. 



163 



tKc only apparent singularity about it being its antenmc^ which are clubbed 

 at the ends. The cast skin of these flies is placed in the cocoonSj even 

 before the insects have left, in a singular position, the head being where 

 the insect lies with its posterior part, so that one would be led to imagine 

 that the insect had turned round in the cocoon after casting its skin, but 

 this cannot be. I hope to obtain information on this point through the pages 

 of "The Naturalist." 



Devizes, June 28fh., 1851. 



ON ODOSTOMIA TRUNCATULA. 



BY H. K. BOLTON, ESQ. 



My spare hours for the last two years have been much occupied in collecting 

 the land, fresh-water, and sea shells of this neighbourhood, and, as far as I am 

 capable, of studying their habits. Permit me therefore to say, that if a few 

 observations, the result of my experience, occasionally contributed to your 

 plea.sing magazine, be at all interesting to the conchologists of other localities, 

 I shall feel much pleasure in affording them. 



I find many here that have escaped the notice, or have not been enumerated, 

 by Montagu, Turton, and others, in their accounts of the shells found in 

 Devon and Cornwall. One has been recently discovered which I have never 

 seen described among our British shells, Odostomia truncatula, of which 1 

 send you herewith a card of specimens. It is found in Plymouth Sound, 

 about two miles from the shore, while dredging among the sand, in rather 

 deep water; and was first observed by a friend of mine, of much practical 

 and scientific knowledge, Mr. Eouse, of Plymouth. The shell consists of six 

 clearly-defined volutions. Mouth, small, oval-oblong; outer margin, thin, not 

 reflected nor forming an umbilicus; apex, blunt or truncated; colour, white, 

 covered with a thin amber-brown epidermis; shell, a quarter of an inch in 

 length, and in form resembling the Bulimus. 



If you have not yet been supplied with a list of the shells of Devon, I 

 shall be most happy in forwarding you one made from my own collection. 

 They are much more numeroas, particularly the minute shells, than has been 

 generally noticed by those who have written on the subject. 



Plymouth, IG, Albert Street, June \^th., 1851. 



We are much indebted to Mr. Bolton for a very fine series of this 

 interesting shell, which is a recent addition to the British Fauna, being first 

 recorded in ''The Annals of Natural History," for 1850, and since introduced 

 into the beautiful work on the British Mollusca, by Professor Forbes and 

 Mr. Hanley, now publishing. — B. JR. M. 



