364 



MOLLUSCA OF DRIFFIELD AND NEIGHBOURHOOD. 



Rev. E. PERCY BLACKBURN. 



Three years' residence (from 1901 to 1904) in the Driffield, 

 section of the East Riding" has g-iven me an idea of the moUusca 

 of the district. A good amount of work has been done in the 

 past by various workers, quahfied and otherwise, and some of 

 the results have been published. But no properly-prepared list 

 is available to-day. In order to help towards such list I give 

 below the result of work done by myself and family. 



But before doing that may I be allowed to urge that 

 the district be more systematically worked. The plan adopted 

 of going ag-ain and again to one place is what is needed. Hap- 

 hazard visits are not enough. Cannot the country-side be 

 mapped out and an area given to a single worker, or, better 

 still, two workers who will make a series of visits with careful 

 observation in wet weather and fine. A uniform schedule as to 

 place, soil, the nature of the waters and vegetation, and any- 

 other local details should be prepared and used by all workers. 

 What is perhaps most needed and offers most opportunity for 

 original research is a series of observations on the habitat, dis- 

 persal, food, and habits of the mollusca, the relation of soil, 

 food, and lack of food to size and colouring. The question of 

 food is an interesting one, and is not by any means exhausted.. 

 Some of these details have been given in part, but the subject is- 

 far from exhausted. 



I have done next to nothing in collecting- any of the Lima- 

 cidcE, Armiidce, and other orders of slugs. Most of the ordinary 

 kinds are found in abundance. 



LiMAX FLAVUS and L. maximus. I have found larg-e specimens in my 

 own garden. 



Arion intermedius is fairly common in the district. 



Agriolimax agrestis is, of course, everywhere. I noticed on several 

 occasions that A. agrestis, which is often straw-coloured, has a way of 

 crawling- up to the top of the grass stems and resting there. At 

 a distance it looks exactly like a head of grass. 



Vitrina PELLUCIDA is found all over, and some of the specimens are 

 uncommonly beautiful. 



V'lTREA CRYSTALLINA can be found pretty nearly anywhere in the district,, 

 and the specimens are usually fine. 



ViTREA LUcmA, supposed to be a South Country shell, we have found at 

 Tibthorpe, and Mr. J. W. Ta}lor emphatically says it is correctly 

 named. 



VlTREA CELLARIA, V. ALLIARIA, and \'. NITIDULA are found in abundance. 

 ViTREA PURA is found commonly. 



Naturalist^ 



