208 PKOF. J. E. MiEE ON THE [vol. lxxV, 



Corhicula and Hippopotamus, and it is one which requires con- 

 sideration. In this connexion reference must be made to the 

 Barrington Beds, which have yielded so rich a mammalian fauna, 

 including abundant remains of Hippopotamus. The occurrence of 

 Corhicula in these beds has been disputed ; but Mr. C. E. Gray, 

 Chief Assistant at the Sedgwick Museum, in 1901 collected mol- 

 lusca from the basal deposits at Barrington : these were identified 

 by Mr. Hugh Watson in 1918. The list is as follows : — 



Arianta arbustorum Linne. Helicella itala Linne. 



Corhicula fluminalis M tiller ? Succinea putris Linne. 



Bithynia tentaculata Linne. Cochlicopa lubrica Miiller. 



Limnsea pereger Miiller. Valvata piscinalis Linne. 

 Pisidium amnicum Miiller. 



There is a query after the Corhicula, but, if not the true flumi- 

 nalis, it is a closely-related variety. 



We may now consider the occurrence of Hippopotamus in the 

 immediate vicinity of Cambridge. It has been recorded in four 

 places, namely, the Old Botanic Gardens Site north of Downing 

 Street, the present Botanic Gardens, Barnwell, and Chesterton. 

 The specimen from the Old Botanic Gardens has been in the Sedg- 

 wick Museum for a long time. The late Prof. Hughes, in a note 

 attached to the Specimen, observed the similarity between the 

 matrix and that of the Hipjyopotamus-he'&ring beds at Barrington, 

 and suggested a mistake in the naming of the locality. The 

 discovery of a similar matrix in beds with Corhicula in the 

 Downing Site grounds, and the recent extraction of the astragalus 

 of Hippopotamus from the present Botanic Gardens, make it most 

 probable that there was no mistake. It must be noted, moreover, 

 that the Old Botanic Gardens specimen was found at a time long 

 before the discovery of the Barrington deposits. Hughes also 

 throws doubts on the Barnwell specimens. He states, in his paper 

 on the gravels of East Anglia, 1916, p. 52 : 



'In our collection . . ., although there are a few specimens of Hippopotamus 

 labelled from Barnwell, there is something* suspicious about them. The bones 

 are not in the same condition as those of the other animals found with them 

 and respecting which we have no doubt.' 



This, however, would be accounted for if, as I believe, the 

 other bones came from a newer horizon in the upper parts of the 

 pits. It is noteworthy that, in addition to Corhicula, JJnio 

 litt oralis and JBelgrandia marginata have been recorded from 

 these Barnwell gravels ; and the occurrence of these shells with 

 Hippopotamus suggests an earlier date for these deposits than 

 that of the associated deposits with the mammoth, woolly rhino- 

 ceros, and their accompaniments. Dr. F. R. C. Reed, in his 

 1 Geology of Cambridgeshire ' 1897, p. 209, records Hippopotamus 

 from Milton Road, Chesterton. He believes that the information 

 was supplied to him by Prof. Hughes, but unfortunately no 

 specimen from this site can be found in the Museum. 



The following mollusca were determined by Mr. A. S. Kennard, 



