( 11 ) 



IV. 



NOTES ON LAND AND FEESH-WATER MOLLUSGA OBSERVED 



IN THE NEIGHBOURHOOD OF ST. ALBANS. 



By G-. E. BuLLEN. 



Bead at St. Albans, 6th March, 1906. 

 (Communicated by A. E. Gibbs, F.L.S.) 



Dtteing the summer and autumn of last year I deroted some 

 little time to the casual study of the MoUusca of this county, 

 and although I entered but lightly upon the matter I was 

 convinced that there lay before me in coming summers a most 

 fascinating field of natiu-al-history study. I feel, however, that 

 in presenting this necessarily brief paper to youi- notice I am 

 trespassing to a certain extent upon Mr. Hopkinson's province, 

 he having devoted, as many of you are aware, much time to the 

 careful study of the land and fresh-water molluscs of the county, 

 and from the localities indicated in his papers many of my 

 specimens were obtained. 



I first spent some weeks in investigating the fauna of the 

 Ver near St. Albans, together with its backwaters, and found 

 specimens in quantity, but there were only a few species. The 

 following is a list of them : — Sphxriutn corneum, S. lacustre, 

 Pisidium amnicum, P. pusiUum, Anodonta cygriea (the swan- 

 mussel), Paludina vivipara, Bythinia tentactilata, B. Leacliii, 

 Valvata piscinalis, Physa fontinalis , Planorhis vortex, P. carinatus, 

 P. complanattis, P. cornetts, Limniea peregra, L. auricularia, 

 L. stagnalis, L. pcdustris, and the little fresh-water limpet, 

 Ancyhis jhiviatilis ; 19 species in all. 



I do not presume that this list is in any way a complete one, 

 but it was compiled after an intermittent period of work extending 

 from May to October. 



The second species of fresh-water limpet, Velletia lacustris, 

 I consider by no means common in the county, it only falling 

 to my lot once to obtain it, this being in a pond opposite to 

 Mr. Ellingham's house on the road from Cupid's Grreen to 

 Leverstock Grreen, although the larger species, Ancylus fiuviatilis, 

 may be found attached to stones in the canal at Boxmoor, in the 

 Ver, and in the Lea at Harpenden, and at Wheathampstead 

 in comparative abundance. I have also taken Physa hynortim in 

 the canal at Boxmoor. 



The amber snail, Siiccinea putris, is fairly common on the 

 rushes bordering the Lea near Harpenden, but I have never 

 taken the allied species, S. elegans, there, although at Boxmoor 

 in August it was extremely common amongst the reeds, together 

 with a true snail. Helix sericea. It was interesting, moreover, 

 to notice that this species appeared to live in companies ; 

 hundreds were distributed over a comparatively close area, 

 whereas a little distance away scarcely a single specimen was 



