446 A THYLACINE OF THE EARLIER NOTOTHERIAN PERIOD, 



In the atlas the vascular foramen beneath the root of the 

 diapophysis is reduced to a minute orifice, but apart from greater 

 size this vertebra presents no noteworthy difference from that of 

 7'. cynocephalus. 



The axis has its postzygopophysial facette directed outwards to 

 an obviously less extent, and its neural arch is longer in propor- 

 tion to the length of the centrum, which has a length of 56 mm. 

 against 54 mm. and a breadth exactly proportionate to that of the 

 living species. 



The total length of the skull and vertebrae present compared 

 with those of the existing species is as 357 to 330, or about Jo- 

 greater, as in the upper series of teeth. Taking this fraction as a 

 constant, the bulk of the individual represented by the remains 

 under view may be estimated at about a fourth greater than that 

 of the modern species. From measurements given above it may 

 be farther inferred that it had a relatively short head, terminating 

 anteriorly in a longer and considerably deeper snout. 



Its variance from the Tasmanian Thylacine is writ large on 

 most of its features, and consequently it can have little of specific 

 moment in common with T. spelceus. If perchance it should 

 eventually appear that the differences now pointed out are in 

 reality exhibited by examples of T. sj^eheus, still, as they have 

 not been published so far, that species has not been so described 

 as to be recognisable, and its name should lapse in favour of the 

 one now proposed, Thylacinus 7'ostralis. 



The cranial remains previously collected and now claiming to 

 belong to the present species are these : — A portion of an aged 

 right maxilla (Cat. No. 12,027) with 2^- in place and the sockets 

 of 2)^ and m^. The length of the tooth and sockets combined is 

 47 "5 mm. against 38 mm. in T. cynocejyhahcs. This maxilla shows 

 that the type does not exemplify the full size attained by the 

 species, since in it the corresponding length is but 44 mm. The 

 palatal surface is transversely concave (Pilton). The dentary 

 process of a left maxilla (Cat. No. 12,028) with all the molars 

 and part of the last premolar. The length of the molar series is 

 53 mm., in the type 59 mm., in the recent species 59*5 mm. 



