THK FROa 



331 



of a reduction and fusion of parts. The teeth, instead of being 

 scattered over the mouth, are found chiefly on the jaws, but 

 tiiere are also a few small patches of 

 teeth on the roof of the mouth. 



The shoulder girdle forms a complete 

 ring extending from the shoulder blade 

 (S.SCP), which lies on the ribs, to the 

 l)reastbone below. To this are at- 

 tached the upper armbones (hu) of 

 the relatively short fore legs. The lower 

 arm is supported by a united radius and 

 ulna. The pelvic girdle is so long as to 

 give great elasticity to the attachment 

 of the skeleton of the long and powerful 

 hind legs, which are used in jumping 

 (fE and Tl. Fl). 



Organs of Nutrition. — The food of 

 frogs is verj' varied, consisting of 

 worms, mollusks, insects, small fishes, 

 tadpoles, etc. These are caught in the 

 roomy mouth, often with the aid of the 

 tongue, which is attached in front and 

 free behind, so that the hind end may be flopped out some dis- 

 tance in front of the mouth to strike an insect (Fig. 312). 



Fig. .312. — Three stage.s 

 (from above downward) 

 ill the movement of the 

 tongue of a frog in catch- 

 ing an insect. From 

 " Cambridge Nat. Hist." 



EX.OC, exoccipital, connecting with vertebral column ; FE, femur ; fon, 

 openings in skull; FR.PA, fronto-parietal ; HU, humerus; IL, ileum; 

 MX, maxilla ; olf.cp, olfactory capsule ; ot.pr, otic process ; p.c.hy, pos- 

 terior horn of hyoid ; PMX, premaxilla ; PR.OT, pro-otic bone (ear) ; 

 RA.UL, radio-ulna; SP.ETH, sphenethmoicl ; SQ, squamosal; S.SCP, 

 suprascapula ; sus, bone suspending lower jaw^ from skull; TtFI, tibio- 

 fibula ; tr.pr, transverse process; UST, urostyle. V.l, cervical verte- 

 bra ; V.9, sacrol vertebra ; VO, vomer ; I-V, digits. B. The fourth verte- 

 bra, anterior face; a.zyg, anterior linking process; en, centrum; Im, 

 lamina; n.sp, neural spine; pd, pedicel; tr.pr, transverse process. After 

 Howes, from Parker and Haswell. 



