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nating below in two tubercles. The phalanx suddenly diminishes in vertical 

 thickness, the sides being convex, the under part slightly concave. The distal 

 articulation is a pulley of three surfaces ; the middle one concave, the two 

 lateral strongly convex : the vertical extent of this trochlea is less than half 

 that of the proximal articulation. The length of this phalanx is a character in 

 which it resembles the second phalanx in the other unguiculate toes, and this 

 resemblance is preserved in the form of the distal articulation, which moreover 

 corresponds with, and can only be adapted to, the short and strong ungual 

 phalanx, which, therefore, I have assigned to the present toe. 



The proximal articulation of the ungual phalanx (ot2, 3) presents a median 

 longitudinal ridge and two lateral canals, overhung by a pointed process con- 

 tinued backwards from the upper part of the base of the bony ungual sheath, 

 so as to preclude effectually extension beyond the straight line : the median 

 articular ridge is continued into a similar but shorter process below, limiting 

 flexion to nearly a right angle ; and the rough margins of the lateral concavities 

 are produced backwards, so that the distal articular end of the supporting pha- 

 lanx is buried in a deep fossa. The base of the ungual sheath swells out at its 

 under part into a thick rugged bed of bone extending along the proximal half 

 of the under part of the phalanx, forming the chief foundation of the claw- 

 process, and developing from its margins the osseous sheath of the claw. From 

 each lateral space between the claw-process and the sheath a large canal is con- 

 tinued downwards, which opens upon the rugged base of the phalanx. The sup- 

 porting process of the claw has the form of a nearly straight, obliquely com- 

 pressed cone, with a very oblique base, reducing the under side to half the length 

 of the upper side ; the two surfaces being separated by a ridge which is most 

 strongly marked on the tibial or inner side. 



The disproportionate shortness of the metatarsal bone of the middle toe (m, 3) 

 is more striking in the hind-foot than even in the fore-foot : but the base wants 

 production from its inner side, which gives the bone of the middle metacarpal 

 its characteristic malleolar figure : in the metatarsus it is laterally compressed 

 between two nearly flat vertical surfaces, and is bent obliquely to the outer side 

 to be wedged between the os naviculare and the fourth metatarsal ; with the pro- 

 duced angle truncated to abut upon the anterior angle of the cuboid bone. 

 There is a large articular surface on the outer side of the base for junction 

 with the fourth metatarsal ; but there is no trace of an articular surface on the 



