84 Mr. Hassall on the Functions performed by the Hairs 



size and opens obliquely upwards, the coronoid process is 

 long as in Spalaa?, the lower incisor runs backwards and out- 

 wards, and the thin layer of bone covering its base forms a 

 protuberance {d) on the outer side of the condyle (e), in this 

 respect resembling both Rhizomys and Spalax. The descend- 

 ing ramus springs from the under side of the alveolus of the 

 inferior incisor, and not from the oviter side, as in the true 

 Bathyergidce. The posterior part of the descending ramus 

 is not directed outwards, as in Spalacc ; but is on the same 

 plane as the horizontal ramus, as in Rhizomys. The molar 

 teeth agree closely with those of Spalcuv, as well as Avith Ba- 

 thyergus, being nearly cylindrical, of equal size, and having 

 but one external and one internal fold of enamel ; the incisors 

 are proportionally broader than in Spalaa^. 



The great difference between the skull of Baihyergus splen- 

 dens and that of Spalax tyjjhius consists in the form of the 

 occiput, it being vertical in the former, or very nearly so ; but 

 I very much suspect that the peculiar form of occiput which 

 we observe in Spalax typhlus (which is the only species of the 

 genus the skull of which I have seen) does not constitute a 

 character indicative of affinity. I think it very likely to vary 

 in the different species of the genus. 



On the whole, it appears to me, that the animal called Ba- 

 ihyergus splendens by Ruppell should be removed from the 

 genus in which he has placed it, and might be arranged either 

 with the species of Spalax or perhaps between that genus and 

 Rhizomys, and I think it probable Rodents may hereafter be 

 found connecting the Bathyergid(B with these genera. 



EXPLANATION OF PLATE IL 



Fig. 2«. howev jaw of Batkye)-giis ca- 

 pensis, viewed from beneath. 



2 h. Side view of do. 

 Fig. 3. Bathyergus splendens of Rup- 

 pell. 



.3 a. Side view of skull. 



3 b. Lower jaw, view from above. 



d. Termination of incisor. 



e. Condyle. 



Fig. L Skull of Orycterus mariti- 

 mus. 

 1 a. Under side of do. 

 1 h. Under side of lower jaw. 

 a, a. Descending ramus. 

 h. Alveolus of ii)cisor. 

 1 c. Lower jaw viewed from above. 

 1 d. Side view of do. 

 Fig. 2. Bathyergus capensis. 



X. — Observations'^ on the Functions performed by the Hairs 

 on the Stigma in Campanulaceae, Compositae, and other 

 Plants. By Arthur Hill Hassall, M.R.C.S.L., Corre- 

 sponding Member of the Dublin Natural History Society. 



1 HAVE read with much interest some observations by M. 

 Adolphe Brongniart on the * Functions of the Hairs on the 



* The principal of these observations were written during the summer of 

 last year. 



