A communication from Mr. R. Lydekker, F.R.S., contained a 

 description of a new species of Ratel (Mellivora) from Central 

 Africa, also notice of the occurrence of a new subspecies of 

 Chevrotain (Dorcatherium) in that district. The author proposed 

 to divide the genus into three geographical races, viz. the typical 

 form from the Gambia, Bates's Chevrotain from the Cameroons, 

 and the present — Cotton's Chevrotain — from the Ituri Forest. 



Mr, H. G. F. Spurrell read a paper entitled " The Articulation 

 of the Vertebrate Jaw," and made the following remarks : — • 

 The object of this paper is to draw attention to the existence of 

 two types of mouth in Vertebrates. In one type the articulation 

 is in the plane in which the teeth meet ; in the other type it is 

 not in the plane in which the teeth meet, but in Mammals above, 

 in Reptiles below that level. This alteration in level is attained 

 iir Mammals by an ascending ramus of the jaw, in Reptiles by a 

 long quadrate bone. The first type is best seen in cai"nivorous 

 Mammals. It allows of a Avide gape and a successive play of the 

 edges of the carnassial teeth from back to front as in the blades 

 of scissors, and is incompatible with lateral movements of the 

 jaw. The second type admits of comparatively slight sepai-ation 

 of the teeth ; it allows all the teeth to meet simultaneously ; and 

 in Mammals it allows of lateral movements of the jaw for tri- 

 turating vegetable food. In the modifications of this type are 

 considered the angle which the ramus forms with the dentary 

 portion of the mandible, the eminentia articularis, and the 

 prolongation forward of the jaws separating the incisor from 

 the molar teeth. These are factors in obtaining the requisite 

 movements of the jaw, especially a greater separation of the 

 incisor teeth, than is required for the molars. 



The next Meeting of the Society for Scientific Business will 

 be held on Tuesday, the 20th February, 1906, at half-past Eight 

 o'clock P.M., when the following communications will be made : — 



1. Mr. L. DoNCASTER, F.Z.S., and the Rev. G. H. Raynor. — 



On Breeding Experiments with Lepidoptera. 



2. Mr. W. P. Pycraft, F.Z.S.— Contributions to the Osteology 

 of Birds. — Part VIII. The Ti-acheophone Passeres, with Remarks 

 on Families allied thereto. 



3. Messrs. Oldfield Thomas, F.R.S., and Harold Schwann 

 F.Z.S. — The Rudd Ex^Dloration of South Africa, — IV. List of 

 Mammals obtained by Mr, Grant at Knysna, 



4. Mr. Bashford Dean. — Notes on the Living Specimens of 

 the Australian Lung-fish [Ceratodus forsteri) in the Zoological 

 Society's Collection. 



