176 On some Species of Inland Mollusca. 



Succinea Pfeifferi^ Eossm. [8. oz;cr/«s, Gonld). 



This lias been very generally known as S. elegans in Eng- 

 land, but the true S. elegans, Risso, is comparatively scarce 

 in this country. 



Gould's Succinea ovalis, which is very common on the 

 North-American continent, is undoubtedly identical with this 

 species, and indeed it would seem that 

 >S'. Pjeifferi or ovalis had its origin, to- 

 gether with such species as Helix pid- Q\ 



ckella and Cochlicopa luhrica, in the \j 



boreal regions of Europe and America, at 

 a time when the two continents were still Si'vcme" ova/is Gould. 



• , 1 a 1 A. „+K^ u A yt. Ihomas, Ontario, 



united. S. elegans, on the other hand, ' 



seems to have its greatest development in central and southern 

 Europe, producing such forms as S. Dunl-ei i, Zeleb., S. hun- 

 garica, Hazay, and S. megalonyxia^ Bourg. In an interest- 

 ing collection of shells from St. Thomas, Ontario, Canada, 

 sent to me by my brother (Mr. D. B. Cockerel!), there are 

 specimens of S, ovalis, which are scarcely to be distinguished 

 from Baudon's var. ventricosa of S. Pfeifferi, and from the 

 same locality such well-known European forms as Conulus 

 fulvus, l)ra]).. Helix imlcJiella, ]\lull. (type form), Cochlicopa 

 luhrica ,^\u\\.,Limna'a trimcatula, Miill. (ot the American form 

 humilis, Say, and an elongated variety resembling rustica, 

 Lea), Plan orb is parvus. Say {=glaher, Jeffreys), and Pisi- 

 dium jmsiUitm , Gmel. { = abditu7n, Hald.), as well as an abun- 

 dance of American species, some very closely allied to 

 European forms, and others peculiarly American, the list 

 including :—Hgal in a indentata, Say; //. eleclrina, (jfO\\\d', H. 

 arhorea, Say ; H. minuscula, Binney ; Helicodiscus lineatus, 

 Say; Conulus chersinus. Say (var.); Helix alternata, Say; 

 H. perspectiva. Say (var.) ; H. striatella, Anth. ; H, mo- 

 nodon, Back, and a distinct variety ; H. alholahris, Say ; 

 Pupa contracta. Say ; P. rupicola, Say ; P. fallax. Say ; 

 Planorhis armigerus, Say ; Pomatiopsis kqjidaria, Say ; Pisi- 

 dium variahile, Prime; Splioerium sfriatinuni, Lam.; S. 

 tumidum, Prime; and aS'. sulcatum. Lam. 



6 Priory Eoad, Bedf. rd Park, 

 Chiswick, Feb. 6, 1887. 



