SKULL 



107 



this is characteristic for the Anura (except Ranodon) as compared 

 with the Urodela. (For the relations of the bones bounding the 

 mouth-cavity, cf. Figs. 77, A and B). 1 



lath* 



tfi-ml 



Pr. ant. 



Corn, princ. 



FIG. 79. A. HYOBRANCHIAL SKELETON OF A LARVAL Rana ttmjwraria, 29 MM 

 is- LENGTH, FROM THE DORSAL SIDE. B. THE SAME OF A LARVA, 15 MM. IN 

 LENGTH, AT THE END OF METAMORPHOSIS, AFTER DISAPPEARANCE OF THE 

 TAIL. C. HYOID CARTILAGE OF A YOUNG FROG, 2 CM. IN LENGTH FROM 

 THE VENTRAL SIDE. 



(All these figures are from wax models after Gaupp.) 



A and B (in part), Branch I IV, branchial arches ; Com. term. I III, terminal 

 commissures of same; Cop, basal plate (copula); Hy, hyoid ; Pr.ant.hy, 

 Pr.lat.hy, Pr.poit.hy, anterior, lateral, and posterior processes of the hyoid '; 

 Spic. IIV, cartilaginous processes. 



B (in part) and C. Corp.cart.hy, body of hyoid cartilage; Corn princ, anterior 

 cornu ; Man, "manubrium"; Pr.al, alary process; Pr.ant, anterior pro- 

 cess; Pr.pott.lat, postero-lateral process; Pr.thyr.pont.med, thyroid or 

 postero-medial process (posterior cornu.) 



The bones of the lower jaw are a dentary and an angular (or 

 angulosplenial). At the distal end of Meckel's cartilage a small 



1 A septomaxillary, helping to close the nasal fenestra on the outer side is 

 present, as in Urodeles (p. 98). 



