?20 MR. B. I. POCOCK ON THE 



characteristic of Ccdlosciunts and Tomeutes. It does not seem 

 to me that its baculum is more Tomeutes -\i\\.e than that of 

 C. noiatus. The partial intergradation between the bacvila of 

 C. prevosti, the type of Calloscmrus, and of T. lokroides, the type 

 of Tomeutes, is effected, as explained below, by C. oiotatus and 

 T. vittatus. (Text-fig. 21, D.) 



The bacula of what may be called the Tomeutes type differ from 

 those of the Callosciurus type above described in having the shaft 

 of the bone shorter and thicker, and the blade deeper and longer, 

 with a shorter hinged area and a longer portion free from the 

 shaft. The shaft is variable in length, being sometimes twice the 

 length of the blade, the point of which falls considerably short of 

 its proximal end or base, or sometimes a little shorter than the 

 blade, the point of which then overlaps the base of the shaft. In 

 all cases probably the glans penis is shorter and thicker than 

 in Gallosciurus. 



In Tomeutes vittatus the glans penis is very like that of Callo- 

 sciuribs notatus, but is relatively shorter and thicker. Its upper 

 and lower edges are parallel ; along its upper runs a sharp carina 

 formed by the edge of the blade of the baculum and ending 

 distally in a short point. On the right side about half-way 

 between this point and the inferior rounded angle of the distal 

 end opens the orifice, which has a little fleshy lobe on its outer 

 side ; and from this a groove runs backwards along the right side 

 of the glans nearly to its proximal end. (Text-fig. 18, I, K, L.) 



The baculum, measuring 14 mm., although conforming in a 

 general way to the typical Tomeutes type of baculum, is more like 

 that of Gallosciurus notatus than any I have seen. The shaft is 

 about twice the length of the blade, very thick at the base, slender 

 beneath the blade, with lightly convex but sinuous inferior 

 border, and upturned at the apex, which is furnished with a 

 small button-shaped thickening projecting an appr-eciable distance 

 beyond the distal end of the blade. The latter, lying in the con- 

 cavity of the upper side of the shaft, has a nearly straight, smooth 

 upper edge, the lower edge, also nearly straight, running obliquely 

 upwards and backwards to meet it in a point. The hinged 

 portion ends inferiorly in an expansion on each side which, as it 

 were, clamps the blade to the shaft, and corresponds to the 

 lateral expansion of the blade seen in Gallosciurus notatus and 

 castaneoventris. This species, Tomeutes vittatus, appears in 

 Thomas's list of unexamined species of Gallosciurus. From the 

 superficial resemblance between vittattts and notatus, he probably 

 inferred that their bacula would be alike. That, however^ is not 

 the case. (Text-fig. 21, E, F.) 



The baculum of a specimen of the type of the genus Tomeutes, 

 namely T. lokroides, from Kursiong in Sikkim, preserved in the 

 British Museum, has a much shorter shaft and bigger blade than 

 that of T. vittatus, and is altogether more specialised. The shaft 

 has a thickened proximal end with the distal third sharply 

 upturned, making a deep, short concavity. The blade, measuring 



