500 Br. C. I. Forsyth 3Iajor — On Fossil T>ormice. 



which in its essential cliaracters as a family shows a more primitive 

 contorniation. 



Whilst it seems to me perfectly justifiable to create a separate 

 genus for the Malta fossil, I fail to see any stringent necessity for 

 removing it from the Dormice, with which, as far as our present 

 knowledge goes, it agrees best in the cranial and dental characters, 

 as well as in the conformation of the limbs. The only other group 

 which comes in question is the Anomaluridas of Winge. But this 

 remark applies equally to the Myoxidge generally, as was long ago 

 recognized by Waterhouse, followed by Gervais. Both these 

 zoologists gave proof of remarkable perspicacity, the former in 

 approximating Anomalurus to the Myoxidse,' the latter in grouping 

 Anomaluriis, ' Myoxus,' and the Tertiary Theridomyinse in one family/^ 

 Flower and Lydekker^ place Anomalurus in the ' Scinromorj)ha,' 

 the Myoxidge in the ' Myomorpha,' and the Theridomyidse in the 

 ' Hystricomorpha.' 



In support of placing Leithia with the Anomaluridee, instead of 

 with the Myoxidse, might be adduced, first, its molariform pre- 

 molars, which are less reduced than even in FJliomys or GUs ; and, 

 secondly, the inner longitudinal ' wall ' of its upper cheek-teeth, 

 which is a peculiar featut'e of Anomalurus, but notot unworn Sciurine 

 molars. These characters we have to weigh against the MyQxine 

 distal union of the tibia and fibula in Leithia. Considering that 

 already within Anomaluridas occur reduced premolars,* and that 

 the aforementioned conformation of the upper molars occurs, within 

 Anomaluridse, in the genus Anomalu7-us alone, we should best meet 

 all the exigencies of the case by classing the whole of the Dormice, 

 Leithia included, at the end of the Anomalurida3 as one of their 

 sub-families, of equal rank with Winge's "Trechomyini, Anomalnrini, 

 Theridomyini, and Pedetini." ^ This is about the place assigned to 

 the Dormice by Von Zittel,^ who, however, constitutes for them 

 and for Winge's Anomaluridre, etc., a provisional sub-order, the 

 Protrogomorpha, a course which has the advantages but also the 

 defects inherent to compromises. And so has the other course 

 followed in the Handbuch, viz., the retention of the terms Sciuro- 

 morpha, 31yomorp]ia, etc., attaching to them, however, a rather 

 different meaning from that intended by Brandt, who unfortunately 

 is still followed by the majority of zoologists. 



For at the bottom of the whole matter, and the cause of all the 

 mischief, are the ' hard-and-fast ' divisions into which the Kodent 

 genera are up to the present day being forced. If we continue to 

 cling to the ' time-honoured ' but unnatural sub-orders Sciuromorpha, 



1 Proc. Zool. Soc. London, 1842, p. 126. 



2 Zool. Pal. Fr., 2« ed. (1859), p. 27. 



3 "Introduction to the Study of Mammals," 1891, pp. 449, 459, 484. 



* For example, in Zenkerella [Aethurus). Cf. "W. E. de "Wintou, "On a ISTew 

 Genus and Species of Eodents of the Family AnomaluridcB " : Proc. Zool. Soc. 

 London, 1898, p. 450. 



= H. Winge, " Jordfundne og nulevende Gnavere " : loc. cit., 1887, p. 118. 



6 "Handbuch der Palaeontologie," I, iv (1893), p. 526. 



