141 



Koala, or the carnivorous Dasyure, save in relative size. They pre- 

 scnt the greatest proportional strength in the Wombat, and the 

 greatest proportional length and slenderness in the Petaurists or 

 Flying Opossums, in \vhich the extreinities are subservient to the 

 support of a dennal parachute. They are also long and slender 

 in the Koala. In general the radius and ulna run nearly parallel, 

 and the interosseous space is very trifling : it is Avidest in the Po- 

 toroos. The olecranon is well developed in all the Marsupiata. la 

 the Virginian Opossum and Petaurists, \ve find it more bent fur- 

 wards upon the ręst of the ulna, tlian in the other Marsupials. In 

 the Wombat, \vhere the acromion is the strongest, and rises an inch 

 and a half above the articular cavity of the ulna, it is extended in 

 the axis of the bone. The distal end of the radius in this animal is 

 articulated to a broad bone representing the os scaphoides and os 

 lunare. l'he ulna, \vhich in the šame animal converges tovvards a 

 point at its distal end, has that point received in a depression formed 

 by the cuneiform and pisiform bones ; these are bound together by 

 strong ligaraents ; and the latter then extends downwards and back- 

 Avards for t\vo-thirds of an inch. The second ro\y of the carpus con- 

 sists cf five bcnes. The trapezium supports the inner digit, and has a 

 small scsamoid bone articulated to its radial surface. The trapezoides 

 is articulated to the index digit, and is wedged between the scapho- 

 liinar bone and os magnum ; this forms an oblique articular surface 

 for the middle digit ; but the largest of the second series of carpal 

 bones is the cuneiform, which sends do\\Tiwards an obtuse rounded 

 process, and receives the articular surface of the fifth and the outer 

 half of that of the fourth digit ; the remainder of which abuts against 

 the obliąue proximal extremityof the middle metatarsal bone. Thefive 

 metatarsal bones are all thick and short, but chiefly so the outermost. 



" The innermost digit has two phalanges, the remainder three; the 

 ungueal phalanx is conical, curved, convex above, expanded at the 

 base, and simple at the opposite extremity. In the Perameles the 

 ungueal iDhalanx of the three middle digits of the hand, and of the 

 two outer digits of the foot, are split at the extremity by a longitudinal 

 fissure, commencing at the upper part of the base. This structure, 

 vhich characterizes the ungueal phalanges in the placentai Pangolins, 

 has not been hitherto met vvith in other marsupial genera. lt would 

 be interesting to examine the skeleton of the newly described ge- 

 nera MyrmecoMus and Chtcropus with reference to this structure. 



" The terminai phalanges of the Koala are large, much com- 

 pressed, and curved ; the concave articular surface is not situated, 

 as in the cats, on the lower part of the proximal end, but, as in the 

 sloths, at the upper. The claws \vhich they support are long. 



" In the great Kangaroo the first row of the carpus is composed, 

 as in the Wombat, of three bones ; but the apex of the ulnarotates 

 in acavityformed exclusively by the cuneiforme. Tliei^e are four bones 

 in the second row, of ■vvhich the cuneiform is by far the largest, and 

 supports a part of the middle, as well as the two outer digits. In 

 Potoroos 1 find but three bones in the distal series of the tarsus, 

 the trapezoides bcing \vanting, and its place in one spccics being 



