( L'i ) 



The metatarsus ascribed by il.M. ilihio-Edwards and Grandidier to Ac. iiigens 

 is only 42 cm. long, while the circnmference of the shaft at the narrowest point is 

 given as 21'o cm. and the width of its proximal end as IS cm., so that tliis bone 

 is considerably stonter in ])ro]iortion to its length than that above described. If 1 

 am right in referring this latter to Ae. titan, this species mnst have been taller 

 and more slender than Ac. ingens, as one might have expected from the great 

 massiveness of the articular ends of the limb-bones, stated to be characteristic of 

 this latter sjiecics. The measurements given by the above-mentioned authors are, 

 unfortunately, insufficient to permit of any comparison being made of the dimensions 

 of the tibiae in the two species, indeed the measurements that are given point to 

 the conclusion that the tibia from which tliey were taken is really that of Ac. titan. 

 The evidenci! upon wliich the association of the bones referred to Ae. ingens rests 

 is not stated. 



Two fairly complete specimens of the femur, both from the right side, are 

 worthy of notice. The smaller of these gives the following measurements : — 



Approximate length 43 cm. 



Circumference at narrowest point . . . 28 „ 



Width of distal end 10 » 



„ ,, shaft at narrowest jwint .... 0'7 „ 



Length from top of neck to lower cud of inner condyle 34 ,, 



This specimen, though a trifle larger, closely resembles that figured ami 

 described in the Froc. Zool. Soc, 1804, pp. 113-115, figs. 1 and 2, a. 



The second is of more slender proportions, and in many respects resembles 

 that figured loc. cit., figs. 1 and 2, //, but in others it is intermediate between the 

 two tyjjcs, so that the importance of the differences between the two forms was 

 ]ierhaj)s over-estimated. The comi)arative sleuderness of the bone renders it not 

 improliable that it may belong to Ae. titan ; if this should prove to be the case, 

 then tliat previously ascrilii'il to this species must belong to some other large form : 

 in any case means are wanting at present for arriving at a decision. 



The dimensions are : — 



Lengtli 47 cm. 



Circumference at narrowest point . . . 28 „ 



Width at distal end 21 „ 



Length from top of neck to lower end of imicr condyle 37'8 „ 



A distal portion of a left tibin-tarsns of great size gives the following 

 measurements : — 



Width of distal end IS cm. 



„ „ shaft at narrowest point . .77,, 



Circumference of shaft at narrowest point . . .21 „ 



This specimen closely resembles that figured in I'roc. Zool. Soc, 1804, PI. xiv., 

 figs. 3 and 4, but is rather more massive. It shows that the lower end of tlic 

 fibula was fnsed with it about 28 cm. above the lower articular surface. 



Some specimens of tarso-metiitarsus similar in size and strnctnrc to that 

 figured loc. cit,, PI. xiv., figs. 1 and 2, call for no special notice ; but tliere is one 

 of a very different form which is of some importance. This bone, which is from 

 the right side, is long and comparatively slender, though less so than a metatarsus 



