926 ROBERT COLLETT, 



In the lower jaw all traces of c and the foremost premolars are 

 wanting. p^ i^ functional, and has 3 rather blunt cusps; the molars 

 are normal. 



In the young, the skull of which has a length of 43mm, 

 breadth 27 mm, there is no trace yet of frontal crests. 



The interorbital space is rather flat and even in width. On the 

 palate the two foramina palatina are already present. 



The dentitiori in the young one is the permanent, the milk teeth 

 having already been shed, although the innermost molar is still un- 

 developed, and ms is just protruding. 



The comparatively large and unworn teeth form an almost un- 

 broken series. Of the incisors, the central ones are still barely longer 

 than the others. The canine is large; the premolars are like those 

 in the upper jaw, p 2 with one, and p 3 with two cusps. 



In the lower jaw the only premolar is placed close to the root 

 of i, and resembles the upper p 3 , but has three distinet cusps. 



The skeletons of both the mature individuals are preserved, 

 although they arrived in a somewhat incomplete condition. The 

 vertebral column in B. is complete, in C. only as far as the 6"* tail 

 vertebra. 



The OS sacrum is formed of 3 almost equally large vertebrae; 

 the 3"^ which has firmly ankylosed to the 2°'^ sacral vertebra (also 

 with its transverse processes), must, however, be properly considered 

 as the 1^* tail vertebra, although in form it very closely resembles 

 the 2'''^ sacral vertebra; the next tail vertebra, which is here called 

 the 1*' , is more slender, and has rather narrow transverse processes. 



The scapula has a characteristic triangulär form, the hinder part 

 being elongated to a an acute and rather long angle, with quite 

 straight sides. Its hinder margin thus, besides being almost quite 

 straight, at the same time is very obliquely inclined towards the 

 upper margin, which has its normal deep curve in towards proc. co- 

 racoideus. -- " 



45. JPetaurista volans (Kerr) 1792, var, minor, 



Didelphis volans Kehb.^ Anim. Kingd. vol. I, p. 199 (1792) [Southei'n Form]. 

 Pe'aurus taguanoides Desm., in : Nouv. Dict. Eist. Nat. tom. XXV, p. 400 



(1818) [Southern Form], 

 Petaurus volans Thomas, in: Ann. Mag. Nat. Hist. (ser. 5) vol. IV, p. 397 



(1879) [Southern Form]. 

 Petaurista volans Thomas, in: Encycl. Britann. 9"' ed. vol. XVIII, p. 728 



(1885) [Southern Form]. 



