S'J'ELKox — List of Land and Freshwater Molliisks of Ireland. 115 



fairly typical (fig. 63) ; but the form 

 ■which prevails in the north-east, and 



WD ED LD AN 

 FE TY AR DO 

 WMSL LE MO 



EM RO CV LH 



WGNG LF WHME 



SC KC KD DU 



CL NT QC CW Wi 



NE LK ST KK WX 



SK MO EC WA 



wc 



more particularly in the Lough Neagh 

 basin (figs. 54, 55), seems referable to 

 the Planorhis diibius of Hartmann (as 

 illustrated by Bourguignat in his " Mala- 

 cologie du lac des Quatre-Cantons") 

 (see fig. 2, below), and has often been, 

 and still is, mistaken for the next species. 

 Hence several of our northern records 

 for Planorbis umlilicatus perhaps belong 

 to this species. The records for Mid 

 and East Cork are omitted for the 

 present, as Mr. Phillips considers all the 

 shells he has so far taken in or seen 

 from these divisions to belong to the 

 next species. 



Fig. 2. — Planorbis diibius Hartmann (n, b) and 

 Planorbis carinatus Miiller (c, d) 

 aftei' Bourguignat. 



Planorbis umbilicatus Miiller. 



Plate VII, fig. 56. 



Helix Planorhis, Brown, Mem. Werner. 

 Soc, vol. ii, p. 523, 1818. Planorbis 

 marginains, Scharff, Irish Nat., p. 152, 

 1892. 



WD ED LD AN 

 FE TY AR DO 



WM8L LE MO 



EM RO CV LH 

 WG NG LF WH ME 

 SG KG KD DU 

 GL NT QG GW WI 

 NK LK ST KK WX 

 SK MG EG WA 

 WG 



The distribution of this shell is 

 almost the same as that of Planorbis 

 carinatus ; but in the southern counties 

 it is much commoner, while in the 

 north-east the reverse is the case, this 

 being the more local species of the two. 

 The habitats of these two shells are 

 apparently different, Planorhis carinatus 

 living in rivers, canals, and lakes, while 

 the present species is almost invariably 

 confined to large ditches and swampy 

 places, and is frequently associated with 

 Planorhis spirorhis var. leucostoma and 

 Aplecta hypnorum. 



Planorbis vortex (Linne). 



Helix Vortex, Brown.Mem. Werner Soc, 

 vol. ii., p. 524, 1818. 



A typical "Central" species, and 

 one which is entirely absent from the 

 north-eastern districts, where so many of 

 this group, ('.('. Central, occur. Some 



[<2 2] 



