374 H. D. REED 



5. The nature and relations of the sound-transmitting appa- 

 ratus indicate that these structures came into their present state 

 in a terrestrial environment. Results gained from this study 

 combined with others tend to confirm the view that the present- 

 day aquatic species are secondarily so; that some species give 

 evidence of just beginning a return to an aquatic abode; that 

 others are still strictly terrestrial and likely to remain so. 



LITERATURE CITED 



Bowers, Mary A. 1900 Peripheral distribution of the cranial nerves of 



Spelerpes bilineatus. Proc, Am. Acad. Arts and Sci., vol. 36, p. 177. 

 Bruner, H. L. 1914 The mechanism of pulmonary respiration in amphibians 



with gill clefts. Morphol. Jahrb., Bd. 48, p. 63. 

 Cope, E. D. 1885 The retrograde metamorphosis of Siren. Am. Nat., vol. 19, 



p. 1226. 



1886 On the structure and affinities of the Amphiumidae. Proc, Am. 



Phil. Soc, vol. 23, p. 442. 



1888 The ossicula auditus of the Batrachia. Am. Nat., vol. 22, p. 



464. 

 Drxjner, L. 1901-'02 Studien zur Anatomic der Zungenbein-Kiemenbogen und 



Kehlkopf Muskeln der Urodelen. Zool. Jahrb., Bd. 15, s. 435. 

 Dunn, E. R. 1917 The salamanders of the genera Desmognathus and Leurog- 



nathus. Proc, U. S. Nat. Mus., vol. 53, p. 393. 

 Emerson, Ellen Tucker 1905 General anatomy of Typhlomolge rathbuni. 



Proc, Bost. Soc. Nat. Hist., vol. 32, p. 43. 

 Gage, S. H. 1891 Life-history of the vermilion-spotted newt, Diemictylus viri- 



descens Raf. Am. Nat., vol. 25, p. 1084. 

 Herrick. C. Judson 1914 The cerebellum of Necturus and other urodele Am- 

 phibia. Jour. Comp. Neur., vol. 24, p. 1. 



1914 a The medulla oblongata of Amblystoma. Jour. Comp. Neur., 



vol. 24,^ p. 343. 

 Kingsbury, B. F. 1905 The rank of Necturus among tailed Amphibia.. Biol. 



Bull., vol. 8, p. 67. 

 Kingsbury, B. F., and Reed, H. D. 1908 The columella auris in Amphibia. 



Anat. Rec, vol. 2, p. 81. 



1909 The columella auris in Amphibia. Jour. Morph., vol. 20, p. 549. 

 KiNGSLEY, J. S. 1902 The systematic position of the Caecilians. Tufts Col- 

 lege Studies, vol. 1, p. 323. 

 Moore, J. P 1900 Postlarval changes in the vertebral articulations of 



Spelerpes and other salamanders. Proc, Acad. Nat. Sci. Phila., vol. 



52, p. 613. 

 NoRRis, H. W. 1908 The cranial nerves of Amphiuma means. Jour. Comp. 



Neur. and Psychol., vol. 18, p. 527. 



