0\ RATS FROM THE SOCIETY'S GARDEXS. 915 



and the distal end of a radius of a small species of Rhinoceros 

 {'^ Acerathe7-li.im), portions of the carapace of a very large 

 Chelonian, probably a species of Testudo, fragments of the shell 

 of Trionyx^ and some Crocodilian remains. 



From some portions of matrix adhei^ent to some of the bones it 

 appears that they are preserved in a bed of tough clay with much 

 calcareous matter and numerous grains of blown sand ; this deposit 

 is probably of lacustrine origin, but in the absence of any molluscs 

 or other invertebrates, it is not possible to be certain either as to 

 its origin or as to its exact age. Judging from the Dbiotherium 

 remains, the beds are probably lower or middle Miocene. If they 

 should fortunately turn out to contain a rich mammalian fauna, 

 probably this discovery will lead to a great advance in our 

 knowledge of the history of several groups of Artiodactyls, of 

 the Hyracoids, and possibly of the Anthropoidea. It is greatly 

 to be desired that a careful collection should be made as soon 

 as possible. 



EXPLANATION OF PLATE XLVIIL 



Fig. 1. Dinothevium hohJej^i, portion of left ramus of mandible with pm. 4, w. 2, m. 3, 

 from above ; 1 a, ditto, from side. Type specimen. 



2. Ditto, crown of ni. 2 of another individual. 



3. Ditto, pm. 3 of the type specimen from above ; 3 a, ditto, from side. 



4. Ditto, crown oi pm.'A of another individual. 

 6, Ditto, left calcaneum from inner side. 



eul., facet for cuboid ; eet., ectal facet ; sus., sustentacular facet ; t.c, tuber calcis. 



All the fif^ures are .\ natural size. 



EXHIBITIONS AND NOTICES. 

 June 13, 1911. 



Edwin T. Xewtok, Esq., F.R.S., in the Chair. 



Mr. H. G. Plimmer, F.R.S., F.Z.S., Pathologist to the Societ}-, 

 presented a Report on the Pathological Examination of Rats 

 [Mus dec nmanus) caught in the Regent's Park and in the Society's 

 Gardens. 500 rats had been examined between the 1st of January 

 and the 17th of Mav, 1911, all in a precisely similar manner. Tli'e 

 spleen, lungs, glands, and blood were examined microscopically ; 

 and from any animal which looked in any way unhealthy cultures 

 were made. 



The results were summarized as follows : — 5 rats were caught 

 in the Park, and 495 in the Gardens : 283 of these were males 

 and 217 females. 



3 rats had tubei'cle, 10 had tapeworm cysts in the liver 49 had 

 Trypanosoma leioisi in their blood, 2 had empyema(not tubercular), 

 1 had a tumour of the lower jaw (the result of an old injury), and 

 1 had pleuritis and hydrothorax (not tubercular). 



