444 



ZOOLOGY 



SECT. 



cal 



cub- 



ctst 



CUTl 



of the Lizard, so that the limb is nearly in the same plane as the 

 fore-limb, and the pre-axial border is internal and the originally 

 dorsal surface anterior. The femur has at its proximal end a 

 prominent head for articulation with the acetabulum, external to 

 this a prominent process the great trochanter, and internally a 

 much smaller the lesser trochanter, while a small process or third 

 trochanter is situated on the outer border a little below the great 

 trochanter. At its distal end are two - prominences or condyles, 

 with a depression between them. Two small sesamoids or fabellcB 

 are situated opposite the distal end on its posterior aspect ; and 



opposite the knee-joint, or articulation 

 between the femur and the tibia, is a 

 larger bone of similar character the 

 knee-cap or patella. The tibia has at its 

 proximal end two articular surfaces for 

 the condyles of the femur ; distally it 

 has also two articular surfaces, one, in- 

 ternal, for the astragalus, the other for 

 the calcaneum. The fibula is a slender 

 bone which becomes completely fused 

 distally with the tibia. 



The tarsus (Fig. 1097) consists of six 

 bones of irregular shape, arranged in two 

 rows, one of the bones the navicular 

 (nav.) being intercalated between the 

 two rows. In the proximal row are two 

 bones the astragalus (ast.) and the cal- 

 caneum (cal.) both articulating with the 

 tibia ; the calcaneum presents behind a 

 long calcaneal process. The distal row 

 contains three bones, the meso-cuneiform, 

 ecto-cuneiform, and cuboid (cub.) ; the ento- 

 cuneiform, which commonly forms the 

 most internal member of this row in other 

 skeleton pi pes. ast. astra- Mammals, is not present as a separate 



gains ; cal. calcaneum ; cub. , 1 



cuboid; cun. cuneiforms; Done. 



There are four metatarsals, the hallux 



or first digit being vestigial and fused with the second metatarsal in 

 the adult. The proximal end of the second is produced into a 

 process which articulates with the navicular. Each of the digits 

 has three phalanges, which are similar in character to those of the 

 manus. 



The ccelome of the Rabbit differs from that of the Pigeon and 



1 In all probability the homologies of these bones are as follows : astra- 

 galus = tibiale + intermedium, calcaneum = fibulare, navicular = centrale, 

 ento- cuneiform = 1st distale, meso-cuneiform = 2nd distale, ecto -cuneiform = 

 3rd distale, cuboid = 4th and 5th distalia. 



FIG. 1097. Lepus cuniculus. 



