90 On the Land and Fresh-water Molliiscd 



the water beside the dhnkhig-places for cattle I find most 

 productive. 



I consider this to be a most unsatisfactory family, and 

 question very much whether it will not be necessary to reduce 

 the number of species to three, and call the others varieties. 



■ 



Unionid.i:. 



Unio pictorum, Linn. — -I have seen shells of this species 

 from the river at Cogge shall, but I have never taken it 

 myself. They were the ordinary form, and I do not think 

 it occurs elsewhere within my boundaries. 



Anodonta cygnea, Linn. — In every stream and many 

 ponds. 



Var. radiata. — In almost stagnant ponds ; at Bromley 

 Lodge vei-y large specimens occur, but I think the shells are 

 thinner than in the normal form. 



A. ANATiNA, Linn., appears to me to be only a variety of 

 the above. The intermediate forms are many, and I think 

 it is only a question of food. I have stocked a suitable pond 

 with anatina, and hope one day to note the result. 



Neritid^. 



Neritina fluviatilis, Linn. — Plentifully on stones in all 

 our streams. The markings are very varied. 



Paludinid^e. 



Paludina contecta. Millet. — In the IStour the specimens 

 are very large, but I do not find it to be an inhabitant of any 

 other stream. 



BYTmNiA tentaculata, Linn. — Very frequent in both run- 

 ning and still waters. The most abundant fossil at Co^Dford. 



B. Leachii, Sliepp. — Occurs in the same habitats as the 

 last species, but is much less abundant. 



Valvatid^. 



Valvata pisciNALis, Miill. — Frcqucnt in all our streams, 

 and in the fossil state at Copford in great plenty. 



