3SG The Penis-bone, or " Bacuhim,''^ in certain Squirrel.<. 



For tvjie I \voul(l select Tomentes Johroides {Sciiirns lok- 

 roides, liodgs.), and, so lar as can now be ascertained, the list 

 of the chief species would be as follows, arranged, as before, 

 into verified species, in the first column, and consequential 

 species in brackets : — 



Tumeutes lokroidcs, 

 „ si mi/ is. 

 „ p/iai/rei. 

 ,, blaiifordi. 



„ p!/;/er!/thri(S. 

 „ jaiiettii. 



„ pii/eri {hippuruR <rroiip.) 



,, philippi)ie)isis (stecrei, juvencus.) 



„ melanogaster ((ilrattis.) 



„ tenuis (pianittts, fraterculus, and many 



others.) 

 „ brookei. 



,, low a. 



„ 7nurinus. 



It is to be hoj)ed that by decrees the bacular characters of 

 the remaining Oriental squirrels may be ascertained, for their 

 skulls and teeth often give little clue to their proper situation. 

 Unfortunately in preparing dry sjiecimens the skin of the 

 penis readily sli|)s off, arid the baculum is thrown away with 

 the carcase, unless the collector has been specially told to 

 save it. The majority of the bacula I have been able 

 to secure, apart from a number carefully preserved by 

 jMr. Shortridge, have been extracted from spirit-specimens. 



I may note that Mr. Shortridge tells me that, so far as he 

 has seen, the species I have put into Tomeutes are, on the 

 whole, more terrestrial in their habits than those of Callo- 

 sciurus, although there are a few exceptions. 



In the preliminary study of this subject that I have so far 

 been able to make, a few points stand out very clearly. 



Firstly, the wide, or at least absolutely complete, separation 

 of the lorms with compound bacula as compared with all 

 the other Sciuritlje, and their comparatively near relationship 

 to each other. Consequently the separation of the Nanno- 

 sciurina; as a subfamily set over against other squirrels ia 

 flatly contradicted by the lomeutes-Wlie bacula of the type- 

 genus, with but little special peculiarity. (The edge of the 

 blade in S. whitelieodi is beautifully serrated, but this is 

 not the case in certain other species.) 



The presence of a simple baculum in Myosciurus minutuSj 

 which is therefore after all not related to the Malayan Nanno- 

 sciurus, and is further evidence of the invalidity of the 

 " Nannosciurinse " as a subfamily. 



