The Amphibian larynx. 317 



Fig. 9. Proteus anguineus. Pharyngeal view of larynx. 



Fig. 10. Proteus anguineus. Cardiac view of larynx. The sheet 

 of muscles dissected ofi. 



Figs. 11 and 12. Proteus anguineus. Laryngeal cartilages of two 

 individuals, showing variation. 



Fig. 13. Siren lacertina. Pharyngeal view of larynx and trachea. 



Fig. 14. Siren lacertina. Cardiac view of larynx and trachea. 



Fig. 15. Amphiuma tridactylum. Branchial arches, larynx and 

 trachea. Ventral (cardiac) view. 



Fig. 16. Amphiuma tridactylum. Lateral view of body in hyoid 

 region, showing the origin of the extrinsic laryngeal muscles. 



Fig. 17. Amphiuma tridactylum. Lower half of tracheal carti- 

 lages from the same specimen as in Fig. 15, but from the pharyngeal 

 side. 



Fig. 18. ■ Amphiuma tridactylum. A portion of one of the lateral 

 tracheal pieces flattened out and drawn in detail, showing lack of con- 

 tinuity. Same specimen as Figs. 15 and 17. 



Fig. 19. Amphiuma tridactylum. Detail of larj^nx and upper end 

 of trachea of same specimen as above , showing separate tracheal 

 elements. 



Fig. 20. Amphiuma tridactylum. Detail from section taken from 

 the lateral wall of trachea in the region represented by the middle 

 portion of Fig. 19. 



Fig. 21. Amphium tridactylum. Portion similar last, more highly 

 magnified, showing degeneration of cartilage between the hyaline 

 portions. 



Fig. 22. Siredon pisciformis. Cardiac view of larynx. Upon the 

 right the layer of muscles has been removed. 



Fig. 23. Menopoma allegheniense. Pharyngeal view of larynx 

 and trachea. 



Fig. 24. Necturus lateralis. Larynx in detail. Pharyngeal side. 



Fig. 25. Salamandra maculosa. Lower end of lateral tracheal 

 piece, flattened out and drawn in detail to show lack of continuity. 



Fig. 26. Amblystoma sp.? Respiratory cartilages. 



Plate 20. 



Fig. 27. Triton alpesfris. Larynx. Pharyngeal aspect. 



Fig. 28. Triton alpestris. Larynx. Cardiac aspect. 



Fig. 29. Triton alpestris. Arytaenoids isolated. 



Fig. 30. Triton alpestris. Dissection of hyoid and mandibular 

 region, showing origin of the extrinsic larjTigeal muscles. 



Figs. 31 — 34. Rana clamitans. Larynx from the pharyngeal 

 side. The successive figures show the gradual removal of muscles. 



Fig. 35. Rana clamitans. Cardiac view of larynx. 



Fig. 36. Alytes obstetricans. Larynx, pharyngeal aspect. 



Fig. 37. Alytes obstetricans. Larynx, cardiac aspect. 



Fig. 38. Rana temporaria. Pharyngeal aspect of laryngeal car- 

 tilages. 



