LACERTA 



107 



The hind limb is similar to that of Triton, but the tarsal 

 bones undergo a modification. The proximal bones are fused 

 into one which is attached to the tibia and fibula ; the distal 

 bones are reduced to two, which become attached to the meta- 

 tarsals. The result is that the ankle can only bend in one 

 place, at the so-called mesotarsal joint. The 5th metatarsal is 



Fig. 49. — Lacerta : pectoral- 

 girdle and forelimb, seen 

 from the left side. 



Fig. 50. — Lacerta : sacrum, pelvic- 

 girdle and hind limb, seen from the 

 left side. 



c, coracoid ; ca, carpals ; cl, clavicle ; /, femur ; fi, fibula ; h, humerus ; 

 ic, interclavicle ; il, ilium ; ip, ischio-pubic foramen ; is, ischium ; mc, 

 metacarpal ; mts, metatarsal (note hook-like shape of that of fifth digit) ; 

 p, phalanges ; pu, pubis ; r, radius ; s> sternum ; sc, scapula ; sv, sacral 

 vertebrae ; t, tibia ; ta, tarsals ; tp, transverse processes of sacral vertebrae ; 

 u, ulna. 



worthy of notice on account of its peculiar hook-shaped 

 appearance. 



Alimentary System.- — The tongue is long, bifid at the tip, 

 and protrusible. It is supported by the " hyoid " skeleton. 

 On the roof of the mouth the palatal folds appear, extending 

 inwards from the sides. At the back of the mouth-cavity, 

 the Eustachian tubes open. These represent the cavity of the 



