112 
JOTJKNAL OF MAMMALOGY 
forms as Phascologale, and in this respect are perhaps most similar to 
those of the saltatorial but otherwise generalized Australian polyproto- 
dont AntechinomySj the myology of which has not been thoroughly 
described. The proportion of tendinous to fleshy parts is about as 
60 is to 40 and the outline of the leg thus resembles that of a digitigrade 
animal. It is markedly different from that of DidelpMs, in which fleshy 
extensions reach nearly or quite to the carpus and tarsus. Specializa- 
tion for terrestrial life has proceeded far beyond that in Peramys, whose 
habits are presumably not greatly different from those of Ccenolestes 
but whose musculature is only slightly different from that of Didel- 
pMs There is some reduction of the intrinsic muscles 
of the feet, especially in the adductorial sets, and the grasping power is 
distinctly limited.’^ On the other hand we have the opinion of Lonn- 
berg, expressed as follows: ^^As already known, Ccenolestes has ar- 
boreal habits. Its feet with their naked, warty soles and the well 
developed pads must be useful in climbing, but the fore feet undoubtedly 
exhibit more pronounced adaptations to the arboreal life. The reduc- 
tion of the claws on the flrst and flfth finger to nails and the displace- 
ment of the latter in direction towards the carpus must be interpreted 
as such adaptations. Although neither the pollex nor the fifth finger are 
directly opposable, they are certainly more free in their movements 
than the corresponding fingers in f . i. Phascogale or some other primitive 
marsupial. They serve therefore without doubt as useful grasping 
organs, and the fifth finger appears to do so even in a higher degree 
than the pollex itself, to judge from the fact that it is more powerful 
and has a better developed pad at its base.’^ 
In brief, if Ccenolestes can climb trees at all it does so not by means 
of the primary arboreal habitus of the Didelphidse and Australian 
diprotodonts, which have well developed divergent hallux and pollux, 
but by a secondary arboreal adaptation involving sharply curved claws 
on the middle three digits of both manus and pes, with strong, deep 
flexors of the digits and partly divergent pollex and minimus in the 
manus. On the other hand, it is perhaps more probable that the strong 
claws on the hands and feet may be used in scratching for insects on 
the ground. Taken as a whole the limbs and feet resemble those of rats 
and insectivores, especially in such particulars as the bowing of the tibia 
upon the fibula, and of the radius on the ulna, with the reduction of 
free movement in both cases. 
Important indications concerning the method of locomotion are 
afforded by the following data supplied by Osgood: In Ccenolestes the 
