THE LIZARD. 149 



95. The carpus, consisting of ten small nodular bones, 

 or rather calcified cartilages ; three of these form a proximal 

 row, the radiale, articulating with the radius, the ulnare, 

 with the ulna, and the minute intermedium between 

 them : five others of much smaller size form a distal row 

 and give attachment one to each of the metacarpals ( 96) ; 

 these are called carpalia, and are distinguished by numbers, 

 that on the radial or preaxial side being carpale i : a 

 ninth bone the centrale, forms by itself a middle row, 

 being intercalated between the radiale, ulnare, and second, 

 third, and fourth carpalia : the tenth bone the pisiform 

 or accessory ossicle is attached to the post-axial side 

 of the distal epiphysis of the ulna. 



96. The bones of the digits : the first or pre-axial digit 

 (pollex) consists of three bones, a metacarpal, articulating 

 with the first carpale, followed by two phalanges ; the 

 second of a metacarpal and three phalanges ; the third of 

 a metacarpal and four phalanges ; the fourth of a meta- 

 carpal and five phalanges ; and the fifth of a metacarpal and 

 three phalanges. 



97. The distal or ungual phalanges have something the 

 form of the horny claws which they support : the remaining 

 phalanges and the metacarpals are rod-like bones, each 

 consisting of a bony shaft and a calcified proximal epiphysis, 

 the distal extremity of the bone being ossified from the shaft. 



XI. Observe the characters of the pelvis as follows : 



98. It consists of two tri-radiate bones, the ossa in- 

 nominata, the dorsal limbs of which articulate with the 

 sacrum, while the two ventral limbs unite, each with its 

 fellow of the opposite side, in the middle line. 



99. The acetabulum, a rounded concave pit, at the 

 junction of the three limbs of the innominate bone, and 

 serving for the articulation of the femur ( no). 



