262 



SCIENCE-GOSSIP. 



FOREIGN VARIETIES OF BRITISH LAND AND 

 FRESHWATER MOLLUSCA. 



BV T. D. A. COCKERELL. 



"V T THILE it seems to me very desirable that the 

 ^ * variations of British mollusca should be 

 named and described, it has sometimes occurred 

 that those who have undertaken this work have 

 not been aware of what has been done abroad, and 

 so have fallen into errors. Unfortunately, no 

 complete list of the named varieties and mutations 

 of our mollusca exists, nor could one be prepared 

 without a great deal of research in some such 

 library as that of the British ^Museum. The 

 writer, however, has a MS. list which is approxi- 

 mately complete up to the middle of 1887, and 

 this, with such additions as have come to his 

 notice, is herewith presented as a pro\'isional list 

 of the foreign varieties of British land and fresh- 

 water mollusca. The slugs are omitted, because a 

 complete list of them will be found in the check 

 list published in 1893. 



It should be clearly understood that the names 

 are cited from the literature, without any attempt, 

 in the great majority of cases, at critical re\ision. 

 Only those who have the specimens before them 

 can undertake to determine which are synonyms 

 and which are wrongly assigned to the species 

 under w^hich they appear. As regards the latter, it 

 is certain that for everj' supposed variety which 

 can be shown hereafter to be a distinct species 

 man}- so-called species will be found to possess only 

 varietal rank. Descriptive notes are given on 

 some of those most likely to be found in England. 



(i) Hyalixia lucida, Drap. 



septentrional IS, Bgt. 



farinesiana, Bgt. 



navarrica, Bgt. 



calabrica, Paul. 



llaimeri, Shuttl. ; France. A little larger, 

 more depressed ; umbihcus larger. 



syriaca, Kobelt. 



convexiuscula, Moq. ; France. A little larger, 

 more convex ; umbilicus a little larger. 



ohsciirata, Moq.; France. Larger, more de- 

 pressed, with a very obscure keel ; umbili- 

 cus larger. 



vequienii, Ivloq. : France. Sometimes larger, 

 very depressed, with a marked keel ; umbili- 

 cus a little larger. 



flamtlata, Stabile. 



(2) H. CELLARIA, Mlill. 



blondiana, Bgt. 



pictonica, Bgt. 



sieversi, Bttgr. ; Caucasus. 



subaperta, Bttgr. : Caucasus. 



chelia, Bgt. 



sancta, Bgt. ; Sj-ria. 



sicula, Kob. ; Sicily. 



villa, Mort. 



silvatica, 'Movch. =eh-vata, Broeck. ; Denmark, 



Sweden, Belgium. Practically identicaj 



with our compacta, Jeflf. 

 obscura, Loc. ; France. Rather darker than 



type, but more transparent ; 9 mm. diam. 

 subalbida, Loc. ; France. Whitish below, 



little transparent, generally large. 

 major, Baud. 

 maculosa, Pascal ; France. Smaller, greenish, 



compressed, with irregular whitish spots 



all over the shell. 

 hypozona, Pascal : France. With a not very 



distinct brown band below. 

 alliaria "Millet,'" Hazay. 

 sylvestris, Gass. 

 jnaculata, Loc. ; France. Horn colour, \nth 



yello\>,-ish flecks. 

 minor, Loc. ; France. Diam. less than 10 



mm. 

 plana, Esmark. 

 alhina, West. Bluish-white, almost opaque; 



practically the same as our vrhite variety. 

 prcRcox, West. ; Italy. 

 chersa, Bgt. ; France, S\'.itzerland, Germany. 



(3) H. HELVETICA, Blum. 



The follo%'.-ing varieties are assigned to H. 



glabra ; some may belong to our species : 

 aquitanica, Chp. 

 anceps. West. 

 barraiidi, Moq. ; S. France, Switzerland, etc. 



Larger, slightly depressed, more strongly 



coloured. 

 hungari:a. West. : Hungary. 

 striaria, West. ; Galicia, etc. 



(4) H. ALLIARIA, Mill. 



? cantabrica. West. 

 anceps. West. ; Sweden. 

 sliepmanni, West. ; Holland. 

 stiballiaria, Bgt. ; Algeria. 



(5) H. NiTiDULA, Drap. 



dutaillyana, Mab. ; France, Switzerland. 



hixCca, Jan. 



ressmanni. West. 



sinistrorsa. Shell sinistral. — See Zool. Record 



for 1879. 

 carthusiana, Loc. Greenish-white, crystalline, 

 opaca, Loc; France. 95 mm. diam., 



completely opaque, milk - white, shiny, 



depressed, with deep sutures. 

 detrita, D. and M. ; France. Small, excoriated 



in places, showing a nacreous tint. 

 alpi:ola, D. and M. ; France. Smaller, more 



strongly striated: mouth more rounded. 

 minor, Stabile. Westerlund gives 6 to 7 by 



3 mm. 

 albina, Kiem. = 7nargaritacea, A. Schm. This 



is our helmii. 

 beryl lus. West. 

 amiatc?, Paul., MS., West. ; Italy. Lat. 8-9 ; 



alt. 4 mm. 

 major. West. ; France, etc. 15 by 7 mm. 

 olearis. West. ; Sweden, Denmark. 

 lundensis, West. ; Sweden. 

 subnitens, Bgt. ; France, Spain. 



