484 Mr. G. Barlee on some British species of Chemnitzia. 



about half-tide way, in corallines or alga;, where it is moat abun- 

 dant. I have taken more than a thousand specimens of all sizes, 

 in \'arious parts of England, Ireland and Scotland, and find them 

 more uniform in size, shape, character and contour, and less in- 

 fluenced by locality, than almost any species I am acquainted 

 with. The Odostomia truncatula, on the contrary, has never been 

 taken but in deep water, and that only in one locality, fourteen 

 miles off the nearest point of land, where it is very abundant ; 

 and although no species presents so remarkable a variation in 

 foiin and sculpture, (no two specimens hardly agreeing, some 

 being without stri?e, others having it upon one or two volutions 

 only, some upon four or five,) yet so characteristic of the species 

 is each specimen, that I challenge any one to deceive me by 

 mixing one of either of the species in question Avith hundreds of 

 the other ; I could detect it at a glance ; indeed the attempt was 

 tried, quite unknown to me, by a very scientific friend of mine 

 at Falmoi;th ; but at first sight I recognized the specimen. 



How will Mr. Clark account for the fact, if, as he says, the two 

 species are identical, of the adult, of a common shell, known for 

 more than forty years, and having so many localities, never having 

 been found, where the young, as he calls them, are so extremely 

 abundant, or where also, in shelly sand, it is taken in vast num- 

 bers of all ages; while with the adult (my Odostomia truncatula), 

 found only at present in one deep water locality, the very fry 

 of the latter are found in great abundance, but all differing from 

 the fi-y of the littoral zone, Odostomia cijlindrica, in form and 

 sculpture, and indeed in conehological character ? The undoubted 

 fact is, they are totally distinct species. 



I am fully aware of the fact, having had ample experience of 

 it, that there are often littoral and coralline zone varieties of the 

 same species ; but then there are always conehological characters 

 in common in both, which are quite unmistakeable. 



As regards Eulimella affinis, I will first refer to what is said by 

 the clever and scrutinizing authors of the ' British Mollusca ' as to 

 Eulimella acicula, with which Mr. Clark unites the former. After 

 alluding to two or three peculiar forms of the latter, which I 

 procured at Stornaway and Plymouth, they proceed to remark, 

 " that were it not for the more slender shape and less peculiarly 

 short volutions, we should have been tempted to annex it to the 

 Eulimella scillce," from which I reasonably infer, that it was the 

 very farthest from their thoughts of allying it (the Eulimella 

 acicula) to my Eulimella affinis, which is the very next species 

 desci-ibed by them. The latter differs from the foi-mer shell in 

 its much broader base, its more rapid increase from apex to base, 

 its more rounded and pi'oportionally shorter volutions, and by its 

 very uniform and conspicuous character of being of a beautiful 



