44 



THE CONCHOLOGIST, 



Var. latior, Jeff. 

 6. Oxford. — Abundant in the canal (S. 

 Spencer Pearce), (J. G. J., B. C). 



ANODONTA, Cuvier. 



Anodonta cygnaea, L. 



Occurs in great abundance, often attaining 

 a large size. 



Var. rostrata, Rossm. 

 6. Oxford. — One specimen in the river 

 oi)posite Port Mcaeiow (Norman, 1853), 

 (Whiteaves, 1857). 



Var. cellensis. 

 6. Oxford. — Railway Lake near Wolvercot 

 (Whiteaves, 1857). 



Var. intermedia, Pfr. 

 6. Oxford. — Near South Hincksey (White- 

 aves, 1857). 



Anodonta anatina, L. 



Quite as common as the preceding species, 

 with which it is generally found. 



DREISSENID.^.. 

 DREISSKNA, Van. Ben. 



Dreissena polymorpha, Pallas. 

 Exceedingly abundant in the canal ; also 

 occurs in the Cherwell. 



NERITID.E. 

 NERITINA, Lamarck. 



Neritina fluviatilis, Linne. 

 I have only obtained this species from 

 two of the divisions, as under : — 



I. Banbury. — River Cherwell (Stretch, 

 1855). On stones in Cherwell 



(Pidgeon, 1875). 

 6. Oxford. — Numerous records, plentiful 

 in the river. 



PALUDINID.-E. 

 PALUDINA, Lamarck. 



Paludina contecta, Millet. 



Not at all plentiful, and only small 

 specimens. 



I. Banbury. — Few in River Cherwell. 



6. Oxford. — (Whiteaves, 1857). Very 



abundant in ditches around Oxford. 



(S. Spencer Pearce). 



Paludina vivipara, L. 



Fairly common, and well distributed. 

 Occurs in large numbers in the canal. 



BYTHINIA, Gray. 



Bythinia tentaculata, Linne. 



An exceedingly abundant and well dis- 

 tributed form. 



Bythinia leachii, Sheppard. 

 Not at all plentiful, and somewhat local. 

 I. Banbury. — (Stretch, 1855), (Pidgeon, 



1875). Occurs sparingly in the canal 



and river. 

 6. Oxford. — Rare (Norman, 1853), (Dalton, 



1855)- Very common (Whiteaves, 



1857). Local and rather scarce (S. 



Spencer Pearce, 1883). 



VALVATID.E. 

 VALVATA, Miill. 



Valvata piscinalis, Miill. 



Abundant wherever it occurs. The records, 

 which are numerous, are confined to dist- 

 ricts Nos. I, 3, and 6. 



Valvata cristata, Miill. 

 A very common and well - distributed 

 species. 



( To be iontiniied. ) 



