1893.J DB. C. J. rOKSTTli MAJOR ON MIOCENE SQCriBRELS. 179 



1. On some Miocene Squirrels^ with Reniarlvs on the Den- 

 tition and Classihcation of the Sciur'mee. By Dr. C. J. 

 Forsyth Major, C.M.Z.S. 



[Eeceived February 14, 1893.] 



(Plates yill.-Xl.) 



I. Introduction, p. 179. 

 II. On the Dentition of tlie Sciurince, p. 179. 



III. Remarks on the Classification of the Sciuridiv, p. 186. 



IV. Descrij^tion of the Fossil Species, p. 190. 



V. Ou the primilire Type of the Sciurine Molar, and of the 

 Eutherian Molar in general, p. 196. 

 VI. Explanation of the Plates, p. 214. 



I. Introduction, 



lu order to deteruiine some remains of Squirrels, collected by 

 myself in the INliddle-Mioceue deposits of La Grive -Saint- Albau 

 (Iscre), it was necessary to compare them with their actual con- 

 geners. I have to thank both l)r. A. Giiiither and Mr. Oldtield 

 Thomas for the kindness shown to me in permitting a close exami- 

 nation of the rich collection of Sciurine skulls in the Zoological 

 Department of the British Museum ; and I am besides under great 

 obhgations to Mr. Thomas, who is so thoroughly acquainted not 

 only with every species, but indeed with every specimen of the 

 collection under his charge, for having liberally favoured me with 

 his experience and ad\ice, especially m regard to intricate ques- 

 tions of synonymy and sjjecific determination. 



The investigation of li\'ing forms has led me somewhat farther 

 than I had anticipated ; so that before treating of the fe\\' fossil 

 remains, it will be necessary to pass in review the numerous, and, 

 in several instances, very unex])ected forms of Sciurine dentition, 

 as well as to present some remarks on their classitication. 



The brachydont teeth of Scln.riitce presenting a Aery primitive 

 type of Rodent molars, 1 Mas naturally led to consider them in 

 tiie light of the pre\ailing theory, the so-called tritubercularity, 

 the rodent molars having been traced, as those of other orders, to a 

 trituberculate type. This forms the subject of the last part of my 

 communication. 



II. On the Dentition of the Sciurinic. 



It is a well-known fact that in various families of the liodeutia 

 tubercular molars — which as a rule are brachydont — and laminated 

 molars — which as a rule are hypsodont or rootless — are met 

 with side by side in closely allied genera and in existing species, 

 whilst in some other Orders we have to look among fossils for 

 the more or less brachydont precursors of th(^ living hypsodont 

 forms. 



It is equally well known, though not always called to mind, 



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