CLASSIFICAXXOX OF TUK SCIURID.-K. 239 



settle the doubtful question as to tlie affinities of tlie genus with 

 Frotoxerus or Funisc'mras. Of the genitalia of Myoscmrus, I 

 know nothing beyond Thomas's statement that the bacnlum is 

 simple as in other African genera. The position of Myrsilus is 

 also doubtful. 



Subfamily Oallosciurin^. 



Grlans penis variable in shape and length according to the 

 baculum ; the orifice close to the tip on the right side. Baculum 

 long and slender or short and stout, slightly or strongly vipturned 

 distally, and always provided with an accessory blade, movably 

 jointed to the concavity of the upper surface. 

 Ears as in Funambulinae. 



Feet, where known, intermediate in structure between those 

 of the more primitive types of the Funambulinte {Funambulus) 

 and the specialised genus Ratiifa. 



Genera: C'allosciurus, Menetes, Tomeutes^ Rhinosciurus, Laris- 

 cus, Lreinomys, Tamiops, Nannosciurus, and probably 

 others. 

 Distribution. Oriental Eegion from India to China and 

 Borneo. 



This group may perhaps be regarded as a specialised oiFshoot 

 from the Funambulinpe. The simplest type of baculum, e. g. 

 that of Callosciurus, may be derived from that of Funambulus by 

 the addition of the blade. But the subterminal position of the 

 orifice is as in the Sciurinre. 



Subfamily Xerin^. 



Glans penis, where known, with a strongly convex crested 

 upper distal edge and a downwardly directed, rounded or truncated 

 apex. Baculum with a stout, longer or shorter subcylindrical 

 proximal portion, and a compressed downturned terminal blade 

 with a median crest above and frequently a laterally expanded 

 upper surface. 



Ears more or less reduced, but with large fleshy antitragal 

 thickening. 



Feet Avith strong fossorial claws and the third digit the longest. 



Fur scanty and harsh. An additional tuft of superciliary 

 vibrissoe over the posterior corner of the eye. 



Genei"a : Atlantoxerus, Xerus, Euxerus, Geosciurus. 

 Distribution. Africa from Morocco to Cape Colony. 



The structure of the penis and baculum alone serves to 

 negative the idea that this group of African Ground-Squirrels is 

 closely akin to certain African arboreal Squirrels, an idea whicli 

 prompted the proposal by Major of such names as Proio^cenos and 

 Paraxurus for two genera of the latter category. The Xerinae, 

 indeed, are in addition distinguishable from the rest of the 



