THE OSTEOLOGY OF VULPES MACROTIS. 417 



this surface obliquely, is intended to lodge the tendon of the peroneus longus 

 muscle. On the external aspect the commencement of this groove is indicated by 

 a deep notch, which in life is converted into a foramen by the ligament stretching 

 across it from the fifth metatarsal to the cuboid itself. 



The scaphoid is a short, subcylindrical segment of some, size, with a round 

 concave facette for the astragalus, and, anteriorly, facettes for the three cuneiform 

 bones, and it articulates with all of these elements. Below, it fuses with a large 

 plantar sesamoid. 



Having a very regular appearance, the three cuneiform bones are wedged in 

 between the scaphoid behind, and the rudimentary hallux, and the second and 

 third metatarsals in front. In point of size, the external cuneiform is the largest, 

 the internal the next biggest, and the middle one the smallest of the three. The 

 internal one develops a conspicuous plantar process for the attachment of ligaments. 

 Anteriorly, it articulates with hallux and second metatarsal. The middle or shortest 

 cuneiform, articulates anteriorly, only with the second metatarsal, while the longer 

 external cuneiform articulates with the proximal end of the third metatarsal. 



Apart from the rudimentary hallux, all of the four remaining metatarsals are 

 long, rather stout, and subcylindrical bones. Proximally, they are crowded close 

 together, practically firmly moulded upon each other for at least one-third of this 

 part of their lengths, and this in such a manner that from side to side they offer 

 dorsally a marked convex surface as compared with the far shallower concave sur- 

 face on their plantar aspects when similarly considered. As they extend forward 

 toward the toes, the two middle ones very slightly part company, and so their 

 shafts keep nearly straight, but the second and fifth each somewhat curve away 

 from the longitudinal median j)lane, and thus their shafts exhibit this curvature. 



The second metatarsal is the stoutest of the four, and the third the slenderest. 

 Third and fourth each have a length of 4.6 centimeters, while second and fifth 

 measure but 4.2 cms. Distally, they present the usual trochlear heads for the 

 articulations of the posterior extremities of the corresponding podal digits. These 

 last each possess two phalangeal joints, and terminate with a freely articulated 

 osseous ungual claw, all morphologically similar to what we find in the digits of 

 man us. 



The character of the articulation between the metatarsal joint and the phalanx 

 in the case of any toe is different from what is found between the two joints of the 

 toe itself. In the first instance the head of the metatarsal bone has a convex, 

 subellipsoidal articulation dorsad, and a sharp, median longitudinal keel on the 

 plantar aspect. The rounded surface articulates with a corresponding facet on the 

 proximal end of the phalanx, but below this, the articulation is deeply notched in 

 the median line in order to admit the aforesaid keel on the end of the metatarsal, 

 and this is kept in place in life by the paired sesamoids and the plantar tendons. 

 The interarticulation between the phalangeal joints themselves is of the simpler 

 trochlear type, such as we find in the case of the joints in the manus or pes of 

 Homo, and between the last phalanx in any toe and its ungual joint the plan is 



53 JOURX. A. N. S. PHILA., VOL. XI. 



