282 ZOOTOMY. 



the second and fourdi still longer, and the third longest of 

 all. The first articulates with the trapezium, the second 

 with the trapezium, trapezoid, centrale, and magnum, the 

 third with the magnum and unciform, and the fourth 

 and fifth with the unciform. Their distal ends present 

 pulley-like surfaces for articulation with the proximal pha- 

 langes, and in the young animal are formed by epiphyses : 

 they have no proximal epiphyses. 



89. The phalanges, of which there are two to the 

 pre-axial digit, or pollex, and three to the other four. The 

 proximal and middle phalanges have hollowed proximal 

 and pulley-like distal articular surfaces ; the distal or ungual 

 phalanges have hollowed proximal surfaces, and have a 

 conical form, the dorsal surface being grooved for the firmer 

 attachment of the horny claw. In the young rabbit the 

 proximal end of the proximal and middle phalanges are 

 formed by epiphyses : they have no distal epiphyses. 



90. The sesamoid bones, small nodular ossicles situated on the 

 palmar side of the joints of the digits : there is a pair between the 

 metacarpal and proximal phalanx, and a single one between the middle 

 and distal phalanges of all the digits except the first ; and one between 

 the proximal and distal phalanges of the pollex. 



X. In the hip-girdle and hind limb note : 



91. The pelvis, or hip-girdle, consisting of the two 

 innominate bones. Each of these consists of an 

 antero-dorsal portion, the ilium, articulated by a rough 

 surface to the sacrum, and of a postero-ventral portion 

 perforated by a large aperture, the obturator foramen, 

 which divides it into a pre-axial (anterior) part, the pubis, 

 and a post-axial (posterior) part, the ischium. In the young 

 animal the ilium, ischium, and pubis are separate bones 

 meeting one another in a triradiate suture in the centre of 



