1897.] HTOBRA>X'HIAL SKELETOIf OF PELODITES PUNCTATUS. 577 



EXPLANATION OF PLATE XXXIV. 



Fig. I. Ewyape bipartita, p. 649. 



2. nigricollis, p. 550. 



3. Lefevrea ceneicolle, p. 627. 



4. Rhevihastiis maculicollis, p. 638. 



5. Biboloides hicolor, p. 553. 



6. Neodera transversicollis, p. 564. 



7. Serraphula cenea, p. 657. 



8. Eugonotes longicornis, p. 559. 

 9, 10. Candezea variopennis, p. 574. 



] 1. Luperus nigrosiUuralis, p. 567. 

 12. Aulamorphiis hollisi, p. 572. 



4. On the Structure and Development of the Hyobranehial 



Skeleton of the Parsley- Frog [Pelodytes punctatus). 



By W. G. RiDEwooD, D.Sc., F.L.S.^ Lecturer on 



Biology at St. Mary's Hospital Medical School, 



London. 



[Eeceived May 3, 1897.] 



(Plate XXXV.) 



When writing recently upon the Hyobranehial Skeleton of 

 Xeno2ms and Pipa I adverted to the fact (16. p. 116) that the 

 hyoglossal foramen so cbaracteristic of these two genera is most 

 nearly paralleled among the phaneroglossal Anura in Pelodytes, 

 and (16. p. 117) that in the hyoidean cornu of Pelodytes is seen 

 the retention of a condition of dissolution which is transient in 

 Pipa. The opportunity for a more exhaustive study of the hyo- 

 branehial skeleton of Pelodytes has since been afforded to me by 

 Mr. Gr. A. Boulenger, F.E.S., of the Natural History Museum, 

 London, who most generously placed at my disposal an extensive 

 series of larvae collected by himself, and in an excellent state of 

 preservation, together with numerous adults of the same species 

 {P. punctatits) both living and in spirit. 



The hyobranehial skeleton of the adult Pelodytes is remarkable 

 in many ways, and, except in the case of the thyrohyals and the 

 postero-lateral processes adjoining, it is difficult at first sight to see 

 what relation exists between the various parts and those of the 

 more familiar hyobranehial skeleton of the Common Prog. The 

 anterior or hyoidean cornu is divided ; and the detached posterior 

 portion, flat and broad in front {li , fig. 9, Plate XXXV.), tapers 

 hackwards into a curved rod of cartilage Qi"), which rises up to 

 he attached to the auditory region of the skull. The study of the 

 metamorphosis of the hyoid arch (postea) shows that in the adult but 

 little is missing of its total length. The only part of the arch 

 which is not represented in the adult skeleton is that between the 

 anterior extremity of the cartilage marked Ji in fig. 9 and the part 

 of the great plate marked h. The relations are readily grasped 

 by referring to the hyoid of the recently metamorphosed animal 

 (fig. 8), where the lateral foramen (Jl, tig. 9) has not yet been 



