A. LEITH AD VMS ON MALTESE LAND-TORTOISES. 



183 





T. rob test a 



6&2- 



T. ephippi- 



um $ . 





millim. 

 r 43 



1 40 



J 55x28 

 \ 45x18 



r 37 



1 25 



millim. 

 35 



36x19 



30 



Largest diameter of the carpal articulation 



Largest diameter of the proximal radial articulation 



It would be interesting to establish comparisons between the 

 Maltese specimens and the recent and extinct Mascarene species, or, 

 in fact, any of the recent gigantic species I have been unable to ex- 

 amine ; the materials, however, as regards the latter are rare in 

 public collections. 



In general characters the radius of T. robusta presents large and 

 expanding articular surfaces. The humeral is concave, and of the 

 outline shown in fig. 2 a. The distal ulnar facet is very pro- 

 minent, thus enlarging the concavity on the ulnar aspect of the 

 bone. The gnarled surfaces for muscular attachments contrast with 

 the general smoothness of the same parts in T. elephantopus and T. 

 ephippium, to a less extent in T. vidua, whilst they at the same 

 time prove that both fig. 1 and fig. 2 belong to fully adult, if not 

 aged individuals. 



The shafts in the fossil bones are round in the middle and flat- 

 tened on their upper and outer aspects. The distal extremities are 

 convex in front (fig. 2) and concave behind (fig. 1). The exten- 

 sive distal ulnar facet is similar to that of T. ephippium, which 

 appears to be relatively larger than that of T. elephantopus. 



A few Tarsal and Carpal bones were found in Mnaidra Gap ; but 

 these are too much broken to be useful for comparison. 



The very large Ungual Phalanges (Plate Y. figs. 5, 6, 7) from 

 Zebbug attest to the dimensions of their owners, and may be safely 

 referred to T. robusta. 



Pelvic Girdle. 



Pubis. 



The following pelvic fragments referable to T. robusta are con- 

 tained in the Zebbug collection : — 



1. A portion of a right pubis, extending from the obturator fora- 

 men outwards (including the process), is 87 millimetres in length, 



