NOTES ON THE WEST CORNWALL DISTRICT. 



By C. E. WRIGHT and LIONEL E. ADAMS, B.A. 



(Read before the Society, April 12, 1905). 



The Land's End is a terra incognita to most conchologists, and would 

 well repay careful working at a more suitable time of the year than 

 January when we made our pilgrimage in search of records to further 

 the completion of the census. 



With the exception of the serpentine promontory at Lizard Point, 

 separated from the rest of the district by the Helford River, the entire 

 formation alternates between shale and granite, both being unpromising 

 from a conchological point of view. The numerous streams, rushing 

 from high inland sources over rocky beds without weed or moss, 

 seem absolutely destitute of bivalves. Several millers and farmers 

 living on these streams assured us that no mussels or shells of any 

 sort inhabited them. Here and there, however, close to the sea we 

 found a few stunted Limncea pereger and Ancylns fliiviatilis. Near 

 Falmouth, in a brackish marsh close to Swan Pool, we found a few 

 poor specimens of the following species Pisidium piisiilum, P. fotiti- 

 nale, Planorbis spirordis var. ecarinata, Limncea pereger and Z. 

 truncatula. 



We searched the small peninsula of Pendennis several times in vain 

 for Hygromia revelata, and also the Porthleven and Helston district 

 which was singularly unproductive of nearly everything except Helix 

 aspersa, which flourishes wonderfully all through the Duchy in spite 

 of the poverty of the soil, and some of the Vitreas, which so often 

 flourish on formations poor in lime,' V. rogersi often occurring in 

 colonies. V. lucida was widely distributed over the whole district, but 

 required digging out of its winter quarters. In this region the animal 

 of this species is remarkably light coloured, often with merely a faint 

 bluish tinge, a strong contrast to the deep cobalt coloured specimens 

 from Tenby and South Devon. 



Hygromia revelata turned up at Nanjizal, about two miles from the 

 Land's End, among grass and moss on the stone walls on the cliff, 

 and we also found it along the wall on the top of the cliff between St. 

 Leven and Porthcurno. Near the latter spot, about half-a-mile inland 

 is the little hamlet called Roskestal, where thirty-four years ago one of 

 us spent the best part of a year in a farm hou.se. Of course we paid 

 a visit there, and while the hospitable people were preparing tea we 

 strolled along the once familiar lane, and there again, close to the 

 house, we came upon Hyg. revelata crawling on the moss which 

 partly covered the old stone walls. 



