CURRENT LITERATURE. 119 



(2) Prophysaon fasciatuni var. obscurum, v. nov. 20 millm. long (in alcohol), 

 like the typical form, but penis-sac narrower and more tapering, and colouration 

 different. Mantle black, with pale marbling at edges ; body grey, very dark 

 above, with obscure dark lateral bands. Sole dark grey. 



Chehalis, Washington, four specimens collected with the last, and sent to me 

 by Mr. Binney. 



(3) Eulimax brand te var. subunicolor, v. nov. Length 34 millm. (in alcohol). 

 Yellowish-ochre, unicolorous, except slight greyish mottling on the back. Keel 

 same colour as body, as also the spotless mantle and unicolorous sole. 



Caucasus; one specimen in British Museum. — T. D. A. Cockereli., F.Z.S., 

 F.E.S., Institute of Jamaica, Kingston, W.I. 



On the Identification of Pisidium nitidum, Jenyns. 



Experience has proved to me that not one conchologist out of every twenty 

 really understands what the Pisidium nitidum, Jenyns, is, and in still fewer 

 collections is it rightly represented. What is usually termed nitidum is a glossy 

 form of P. pusillum, which is not at all uncommon. P. nitidum is the rarest of 

 our British Pisidia, and the only species that may be described as always 

 possessing a distinctly white foot. This organ in P. amnicum, Mull., P. fontinale, 

 Drap., P. henslowanum , Shepp., and P. cinereum, Alder, being usually tinged 

 more or less with grey, while in P. pusillum, GmeL, and P. milium, Hald. 

 (= P. roseum, Jeffreys) it is often orange-yellow or rose-colour, otherwise there 

 is nothing of special note about the foot or mantle, the latter, like that of most of 

 the Sph&riidcE, is fringed with a grey line. 



The most distinctive external feature, perhaps, is the form of the siphon. It 

 is a short funnel-shaped tube, the mouth of which is patulous, crenated, and 

 distinctly plicated. " These appearances," says Jenyns, " are not always obvious, 

 unless the siphon is protruded by the animal to its utmost extent ; the mouth of 

 the tube, which is rendered very dilatable in consequence of the plaits, then 

 becomes fully expanded, and the irregularity of its partially reflexed margin is 

 rendered distinctly visible." After the animal has been killed in boiling water, 

 by a little careful manipulation, and with the aid of a pocket lens and a couple of 

 fine needles, most of the above-mentioned features can be easily made out. 



The shell is smaller than that of P. pusillum and seldom varies. It is thin, 

 and marked with numerous fine regular, concentric stride ; the epidermis is very 

 thin and extremely glossy, the umbones are prominent, broad, blunt, and swollen, 

 encircling them are three or four yellowish-white coloured strire, marking them 

 off somewhat conspicuously : the anterior side is somewhat truncate and rounded ; 

 the posterior side very slightly produced, abruptly sloping downwards, and the 

 ventral marmn rounded. — Walter E. Colljnge. 



CURRENT LITERATURE. 



In order to make the following Bibliography as complete as possible, the 

 Editor invites the assistance and co-operation of British and foreign authors. All 

 communications should be addressed to The Editor, the " Conchologist," Mason 

 College, Birmingham, England. 



MALACOLOGY IN GENERAL. 



Simroth, H. — Bronn's Klassen und Ordnungen des Thier-Reichs. iii-, Mollusca. 

 Re-written by Dr. H. Simroth. Parts i. and ii., pp. 1-96. Leipzig, 1892. 



Simroth commences the new edition of Bronn's " Mollusca " with a review of 

 the history of Malacology. He recognises three eras: — (1) The prehistoric (or 

 culinary !) era, as evidenced by the shell-mounds of prehistoric man ; (2) the era 

 of collection and crude systematisation, from Aristotle to nearly the close of the 



