CLASSIt'ICATION OF THE SCIURID.E. 211 



to Ficnisciurus (= Paraxerus Major) and others to Major's 

 section a of the genus Sciurus, for which Trouessart's name Helio- 

 sciurus was available. The interest of this paper lies in the 

 circumstance that two authors working on the same material and 

 using the same characters, namely skulls and teeth, came to very 

 different conclusions. De Winton also commented on the 

 curiosity and inconvenience of the fact that in the African 

 Squirrels that approach Xerus in harshness of fur the skull and 

 teeth are Sciurus-like, whereas those with softer fur approach 

 Xerus in cranial characters. 



In a paper upon the African Squirrels (Ann. Mag. Nat, Hist. 

 (8) iii. pp. 467-475, 1909) Thomas revised de Winton's and 

 Major's conclusions with respect to the Ethiopian species. As 

 the result of a more exhaustive examination, he came to the 

 conclusion, mainly on the evidence of skulls and teeth, that no 

 fewer than twelve genera should be admitted : — Sciurus for 

 poensis and two others ; Heliosciurus for gamhianus, inmctatus^ 

 rufohrachiattbs, etc. ; Myrsilus for auhinnii and one other ; Funi- 

 sciurus for isaieUa, leucostigma, lemniscatus, etc. ; Paraxerus for 

 cepapi, palUatits, pauli, etc. ; Protoxeras for stangeri alone ; 

 Ep>ixerus iov ebii and loilsoni; Atlantoxerus for getulus; Xerus 

 for hrachyotus and rutilus ; Geosciurus for capensis ; Etuverus for 

 erytliropus and viicrodon ; Myosciurihs for ininutus. 



With the exception of Myosciurus, retained in the subfamily 

 Nannosciurinte, all the rest wer-e referred to the Sciuriiice. But 

 the genera of Sciurinae were divided into two sections, A and B, 

 B containing the four genera Atlantoxerus, Xerus, Geosciitrus, 

 and Euxerus, distinguishable from the rest of the Sciurime by 

 their coarse fur and ci^anial characters. 



In connection with these attempts to arrive at the truth with 

 regard to the affinities of the species of Squirrels, it may be noted 

 that both Forsyth Major and Thomas retained a certain number 

 of typical African and Asiatic forms in the genus Sciurus, of 

 Avhich S. vulgaris in the type. This affiliation resulted from the 

 evidence supplied by skulls and teeth ; but the conclusion very 

 forcibly suggested by the literature of the subject is the un- 

 trustworthiness of such characters. 



This conclusion as applied to typical Squirrels was confirmed 

 by Thomas in 1915 (Ann. Mag. Nat. Hist. (8) xv. pp. 383-387) 

 from a study of the penis bone or baculum. To the details of 

 this paper I shall refer in the following pages; but attention 

 may here be drawn to one or two important points that were 

 clearly brought to light : — (1) None of the tropical African* or 

 Asiatic species, except Rlieithrosciurus, shows any near affinity to 

 Sciurus. (2) All the American Squirrels i-anging from Canada 



* To tlie African species assigned to Sciurus in 1909, Thomas subsequently gave 

 the name ^tliosciurus, with poensis as the type (Ann. Mag. Nat, Hist. (8) xvii. 

 p. 271, 1916), and in 1918 (Ann. Mag. Nat. Hist. (9) i. p. 33) he dismembered the 

 black-striped species of Paraxerus from that genus, calling them Tamiscus. 



