1^90.] COLLECTED BY DR. EMIN PASHA. 449 



were simply adult and young o£ the same animal. But in their skulls, 

 as in other cases in the present family, the age characters are so slight 

 and doubtful that one would at first sight say that the skull of h 

 was that uf an adult animal ; and therefore that it could not possibly 

 be of the same species as the very much larger one of a. Purther- 

 more, h agrees in every respect, external and cranial (except that 

 it has not the white frontal spot), with the tj-pe of Geonjchus 

 albifrons, Gray, in the British Museum ; and, on the other hand, 

 a agrees in its skuU and dentition with that of G. 'pallidum, Gr., 

 which is unquestionably synonymous with Peters 's IJdiojihobius 

 aiv/enteo-cinereus. The colour of 6r. pallidus, and, so far as can be 

 judged from the figure and description, that of H. argenteo-cinereus, 

 is very much paler than either of Emin's specimens, and this by 

 itself makes it doubtful whether the latter are certainly of the same 

 species. Without further material, however, it would not be safe to 

 separate them on account of their colour alone. 



But the difiSculty arises owing to the number of the teeth. In 

 Peters's examples, in the type of G. j^allidus, and in a of the present 

 collection there are either five or six cheek-teeth, as in typical 

 Myoscalops, while in the G. albifrons and in b there are only three 

 or four, as in Georychus. But the peculiar structure of the posterior 

 palatal region is quite the same in both, as also are the proportions 

 of the digits ; and I am therefore induced for the present to look upon 

 the two smaU specimens as merely younger examples of M. argenteo- 

 cinereus, and to suppose that as they got older they would have 

 developed more and more of their posterior molars. 



The peculiar way in which the teeth of Myosmhps succeed each 

 other behind up to a total of six renders the true homologies of the 

 four cheek-teeth of Georychus a little doubtful, and instead of there 

 being three molars and one premolar as is ordinarily supposed, it 

 seems possible that there are really three premolars and one molar, 

 the two molars suppressed being those that only come up in extreme 

 old age in the allied genus Myoscalops. 



Finally, should the difference in colour already referred to prove 

 of specific value, the type of " G. paUidus " would fall under 

 M. aryenteo-cimreus, while the dark-coloured species would stand as 

 M. albifrons, to which both of Emin's specimens would then be 

 referable. 



20. Atjlacodus swrNDERNiANTTS, Temm. 

 a. Monda, J^guru Mountains. 



21. Pbocavia bocagei. Gray. 

 a. $, Usambiro. 3/9/89. 



" Iride fusco-umbrina. Pound on the rocky hills round Usambiro. 

 Native name ' Pembe.' "— E. 



This is a very considerable extension of the known range of 

 P. bocagei ; but Dr. Emin's specimen agrees on the whole so fairly 

 well with the Angolan examples in the Museum that I do not at 

 present feel justified in separating it specifically. 



