VI.] 



THE COMMON FROG. 



6i 



appendages. Now both layers of the skin of the 

 common Frog are entirely soft and utterly destitute 



Fig. 26. — Dorsal surface of the Cara^jace ot a Fresh-water Tortoise (Emys). 1—8, 

 expandf-d neutral spires ; r^ — >^, expanded ribs ; mi, first median (or nuchal) 

 plate \ py, last median (or pygal) plate; m, marginal scutes. The dark lines 

 indicate the limns of the plates of the horny epidt-rmal tortoise-shell; the thin 

 sutures indicate the lines at ihe junction of the bony scutes. 



Fig. 27. — Dactylctln-n cnpensis. 



