Mr. Alder's Catalogue of Land and Fresh-water Shells. S9 



CATALOGUE. 



Class. MoLLuscA. 

 Order. Trachelipoda. 

 Fam. Peristomiana. 



Gen. PALUDINA. 



1. P. impura, Lam. 



Helix tentaculata, Linn. 

 In ditches and ponds ; rather rare. Prestwick Car, Haddrick's Mill-stream, Ouseburn. 



Gen. VALVATA. 



2. Y.piscinalis, Lam. 



Turbo fontinalis, Mont. 

 In ponds and slow streams ; rare. Ouse Burn. 



3. V, cristata, Mull.* 



V. planorbis, Drap. 

 Helix cristata, Mont. 

 In ditches and ponds ; rare. Prestwick Car. 



Fam. Lymnjeana. 



Gen. LYMN^A. 



4. L. stagnalis, Drap. 



Helix stagnalis, Linn. 

 In ponds at Prestwick Car. 



A smaller and more slender variety of this shell also occurs as above, answering to 

 the Helix fragilis of Montagu, who has most probably mistaken the Linnaean species. 



5. 1.. palustris, Drap. 



Helix palustris, Linn. 

 In ditches and marshes ; not uncommon. 



6. L. leucosfoma, Lam. 



L. elongatus, Drap. 

 Helix octanfracta, Mont. 

 In ditches and ponds ; frequent. 



7. L. minuta, Drap. 



Helix fossaria, Mont. 

 In ditches; common. 



* The references to MuUer's species have been made through the medium of other authors. 



