DEGEXEKATION I\ LIMBS OF LIZARDS. 



273 



ClIAMAESAUHA MACUOLEPIS. 



Eeduction lias proceeded further in this species than in the 

 two preceding (Fig. 4). The fore-hmbs have entirely disappeared, 

 though the corresponding pectoral girdle has been found to be 

 present in its entirety. Outwardly the hind-legs are styliform 

 and measure only 6 or 7 mm., and are wholly undivided, termin- 

 ating in an extremely minute claw. On dissection it is found 

 that all the digits have disappeared except one. From its 

 symmetrical position and from comparison with the stages in the 

 previous species, this is regarded as the third or middle of the 

 pentadactyl series. Only two phalanges, however, are present, 

 the second being vestigial, and but a single metatarsus occurs. 

 The tarsus is represented by a single undivided bone which, from 

 comparison with the condition in the hind-limb of C. anguina, is 

 probably to be regarded as the fused tibiale and fibulare, the 

 distal tarsaha having wholly disappeared. The bone extends 

 partly upwards on its post-axial side in order to reach the fibula, 

 which is somewhat shorter than the tibia, as if it were already 

 started on a course of defeneration. 



Fig. 4. — Hind-limb of ('fu/inaesai/ra macrolepis. 

 fern, feniui-. t. til)ia. /. filmla. fur. tarsus, mt. metatarsus. III dio-it. 



