126 ME. W. a. RIDEWOOD ON THE HTOBEA.NCHIAL 



EXPLANATION OP THE PLATES. 



Plate 8. 



Mg. L Xenopus Its vis, female. Hyobranchial and laryngeal skeleton, ventral 

 view. (X3.) 

 2. Xenopus Imvis, female. Right half of laryngeal skeleton, seen from 

 ■within. ( X 3.) 



5. Xenopus lcBvis,iem.ale. Laryngeal skeleton, dorsal view. (X3.) 

 4:. Xenopus lavis, mdle. Laryngeal skeleton, ventral view. (x2|.) 



6. Xenopus lesvis, male. Laryngeal skeleton, in median section. ( X 2^.) 

 6. Xenopus levis, male. Laryngeal skeleton, dorsal view. (x2|-.) 



In figures 2 and 5 the cut surfaces are marked by diagonal shading. 



Plate 9. 

 Fig. 1. Pipa americana, female. Hyobranchial and laryngeal skeleton, ventral 

 view. (X3.) 



2. Pipa americana, female. Laryngeal skeleton, dorsal view. ( X 3.) 



3. Pipa americana, female. Laryngeal skeleton, median vertical section. 



(X3.) 



4. Pipa americana, male. Internal or ventral view of the roof of the 



laryngeal skeleton, cut as indicated by the dotted line in fig. 6- 



(xU.) 



5. Pipa americana, male. Dorsal view of laryngeal skeleton after removal 



of the roof. (xl|.) 



6. Pipa americana, male. Laryngeal skeleton, seen from the left side. 



The dotted line indicates the plane of section of figs. 4 and 5. ( X 1|-.) 



7. Hana esculenta, female. Eight half of the laryngeal skeleton in median 



section. ( X 4.) 

 In figs. 3, 4, 5, and 7 the cut surfaces are marked by diagonal shading. 



Beference letters to Plates 8 and 9. 

 a. Ala, or great wing of the hyobranchial skeleton. 

 ap. Antero-lateral process of the basal plate. 

 ar. Arytenoid cartilage. 



ar' . Posteriorly-directed process of the arytenoid cartilage. 

 hi. Blinker-shaped process of the cricoid cartilage. (" Scheuklappenartiger 



Fortsatz" of Henle.) 

 br. Bronchial cartilage. 



c. Dorsal or roofing portion of the cricoid cartilage, 

 c'. Anterp-ventral portion of the cricoid cartilage. 

 e". Postero-ventral portion of the cricoid cartilage. 

 ch, Ceratohyal or anterior cornu. 



ch'. Median rod of cartilage formed by the union of the anterior cornua. 

 er. Crest arising from the floor of the larynx. 



d. Process of the arytenoid to which the dilator muscle is attached. 

 pp. Posterior epiphysis of the thyrohyal. 



./. Membranous area in the side-wall of the larynx. 

 /'. Membranous area in the floor of the larynx. 



