248 MOLLUSCA OF NORTHAMPTONSHIRE. 



(5). Isolated records from other sources, each of which is 

 duly credited to its recorder. 



It will be seen on referring to the map of the county that 

 much the greater part of its area is as yet uninvestigated, for a 

 radius of seven miles from their common centre will cover all the 

 localities investigated by Messrs. Slater, Crick, and Rogers, while 

 a radius of three miles will include all those worked by Mr. Bell, 

 which moreover are on the extreme edge of the narrowest end of 

 Northamptonshire. 



The number of species and varieties recorded hereafter are 

 as follows : — 



Water Shells ... 30 species and 6 varieties. 



Slugs 4 „ 2 „ 



Land Shells ••• 37 „ 17 „ 



Total 71 25 



This enumeration does not include the numerous colour 

 and band mutations of Helix nemoralis and H. hortensis. 



The species whose absence from the enumeration is most 

 conspicuous and which are therefore the most likely to be added 

 to it by further research are the following : — 



Pisidium, various species Limax flavus, 



Anodonta cygnea. L. lasvis. 



Valvata cristata. Lehmannia arborum. 



Physa hypnorum. Zonites glaber. 



Planorbis nitidus. Z. nitidus. 



Ancylus lacustris. Helix pygmsea. 



Amalia marginata. Vertigo, various species. 



The Conchological Society's referees will be happy to have 

 the opportunity of examining and determining any or all of the 

 above. There also seems no reason why Testacella should not 

 occur, while Cyclostoma has been reported but not confirmed, 

 and Achatina and Acme should be searched for. 



The initials appended to the records are those of T. W. Bell, 

 W. D. Crick, R. Rogers, and H. H. Slater. 



J.C, iv., Oct., 1884. 



