1907.] ANATOMY OF THE PELOBATID^E. 901 



The slender petrohyoideus posterior primus seems to be 

 attached to the body of the hyoid just above the articulation of 

 the thyrohyaL 



In Xeno'plirys monticola the petrohyoideus posterior primus is 

 separated by a wide gap from the petrohyoideus anterior. The 

 middle and posterior slips of the former are about equal in size ; 

 but the latter runs in cjuite a different direction, passing below 

 the end of the thyrohyal as is shown in the accompanying 

 figure (text-fig. 238, p. 898). 



Megalojihrys montana is so much like M. nasuta (text-fig. 240, 

 p. 902) that a special description is hardly needed. The differences 

 from the last two types will be obvious. 



The subhyoideus and the petrohyoidei of Pelohates fuscus are 

 different from those of the Oriental Pelobatidje. Owing to the 

 absence of the anterior cornua of the hyoid in Megalojihrys nasuta^ 

 the subhyoideus is attached to the lateral walls of the skull. In 

 Pelohates, on the other hand, as is shown in the figures of Ride- 

 "Vvood * and Boulenger t, there is a detached piece of cartilage, in 

 shape like the sound-holes of a violin, on either side which 

 represents the posterior region of the anterior cornu. To the 

 posterior extremity of this is attached the subhyoideus, thus con- 

 firming the morphological views held with regard to that piece of 

 cai-tilage. Pelohates fuscios has the usual four pairs of petro- 

 hyoideal muscles. Of these the petrohyoideus anterior needs no 

 special comment. The three slips of the petrohyoideus posterior 

 are slender muscles as in Pana, and, as is also partly the case in 

 that genus, are all attached to the thyrohyals. And furthermore, 

 again as in Patia escidenta, the petrohyoideus posterior tertius is 

 practically entirely inserted upon the end of the thyrohyal. As 

 in Xenophrys, the long cartilaginous epiphysis of the thyrohyal — 

 inadequately represented by Boulenger J and Ridewood § — lies 

 between the second and third divisions of the petrohyoideus 

 posterior. 



§ Larynx. 



In my paper upon Megalophrys nasuta I did not deal with the 

 larynx of that Frog. I desire therefore in the present place to 

 suj)plement that deficiency by a few facts. The laryngeal 

 cartilages present us with several difierences from those of other 

 Frogs. Pana has naturally been taken as the type of the 

 Anuran larynx, and until recently Wiedersheim's|| figures of the 

 same. These latter have, however, been shown by H. H. Wilder 

 to be representations of a type " entirely unique"^. The more 



* P. Z. S. 1897, pi. xx-x-v. fia-. 12. 

 t Ray Soc. Monog-raph, p. 197, fig. 75. 

 X Loc. cit., fig. cit. 

 § Loc. cit., fig. cit. 



\\ In the various editions of his two text-books. 

 1l Zool. Jahvb., Abth. f. Anat. ix. p. 288. 



