REPORT ON THE MARSUPIALIA. 77 



Carnivora. 



Of the Carnivora I have examined the feet of the domestic Dog (Cards familiaris) , 

 the Dingo (the Australian Wild Dog), the Cat (Felis catus), the Puma (Felis concohir), 

 the Leopard (Felis leopardus), the Lion (Felis leo), the Otter (Lutra vulgaris), the 

 Badger (Meles taxus), the Pole-Cat (Mustela putorius), and the Walrus (Trichechiis 

 ■rosmarus). In the last four the foot is pentadactylous, whilst in the others it is tetra- 

 dactylous— the hallux being only represented by a rudimentary metatarsal. 



Let us, in the first instance, direct our attention to the tetradactylous Carnivora. In 

 these the metatarsal bones are placed in such close apposition, that the intrinsic muscles 

 of the pes are situated almost entirely upon the plantar aspect of the metatarsus. In the 

 Dog, indeed (PI. VIII. fig. 4), it is with difficulty that the point of a knife can be 

 introduced into the interosseous spaces. In the Cat, Puma, Leopard (PI. VIII. fig. 7), 

 and Lion, whilst the bones are in actual contact towards the tarsus, yet they open out 

 towards their phalangeal extremities, and in the narrow eliptical spaces thus formed, the 

 thin, sharp edges of the dorsal interossei maybe seen reaching half-way up the interosseous 

 spaces (PI. VIII. fig. 7, d s to cP). 



Owing to this arrangement of the metatarsal bones, the intrinsic muscles are crowded 

 into the sole ; further, the clear definition between the three typical layers is in a great 

 measure lost. None of the muscles are suppressed, but fusion has taken place between 

 several which in other feet we have seen as separate and distinct factors. The cause of 

 this fusion, however, cannot be assigned to crowding, because in Phascogale, and especi- 

 ally in Dasyurus, the condition of the metatarsus is very similar, and yet all the intrinsic 

 muscles have retained their individuality in spite of the limited space they occupy. 



Plantar layer. — In all cases the adductor muscles remain as a distinct plantar layer, 

 and they are arranged so as to adduct towards a line drawn through the medius. 

 Generally they are two in number, — viz., (l) the adductor minimi digiti (PL VIII. 

 fig. 8,p 5 ) ; and adductor indicis (PI. VIII. fig. 8,p 2 ). Occasionally a third is to be found 

 in the Dog — an adductor annularis ; but this is feebly developed, and always more or less 

 fused with the tibial head of the flexor brevis of that toe. This seems to indicate that in 

 the other animals this muscle is lost by fusion and not by suppression. These adductor 

 muscles, whether two or three in number, all arise by a common origin in the middle line 

 of the foot from the ligamentous textures at the base of the metatarsus, and then diverge 

 from each other to reach their respective points of insertion. 



Associated with the plantar layer is the opponens minimi digiti (PI. VIII. fig. 8, o.rn). 

 It is a narrow band of fibres which arises in common with the adductor of the little toe, 

 and is inserted into the plantar face of the distal third of the shaft of the iifth metatarsal 

 bone, under cover of the flexor brevis minimi digiti. This muscle was found in all the 

 tetradactylous Carnivora mentioned above. 



