644 



THE AMERICAN NATURALIST [Vol. XLIX 



modern Amphibia existing in New York and in Cali- 

 fornia ; for in these states we find modern genera in com- 

 mon. This wide diversion of structure between the faunas 

 of Linton and Mazon Creek is not due to difference in age, 

 since it is almost assured that they were nearly contem- 

 poraneous geologically. 



The high degree of specialization attained by various 

 members of the Coal Measures Amphibia is remarkable. 

 They had become adapted to nearly every condition of 

 vertebrate existence, which animals of later times have 

 adopted. There were strictly aquatic, fossorial, terres- 

 trial, climbing, crawling, worm-like, snake-like, lizard-like, 

 crocodile-like, all living contemporaneously. The absence 

 of fish like tonus is noteworthy. 



1. Watson, D. M. S. 1912. The Larger Coal Measure Amphibia. Mem. 



and Proc. Manchester Lit. and Philos. Soc, LVII, No. 1, pp. 1-4, 1 pi. 



2. Broom, K. 1913. On the Structure of the Mandible in the Stegoceph- 



alia. Anat. Am.. Bd. 45, Xo. 2/3, pp. 73-78, figs. 



3. Gregory, W. K. 1911. The Limbs of Enjops and the Origin of Paired 



Limbs from Fins. Science, N. S., 33, No. 848, pp. 508-9. 



4. Gregory, W. K. 1913. The Crossopterygian Ancestry of the Amphibia. 



Science, X. S., 37. Xo. 960, pp. 806-8. 



5. Pollard, H. B. 1891. On the Anatomy and Phylogenetic Position of 



Polypterus. Anat. Am., Bd. VI, p. 338; Zool. Jahrb. (Morphol. 

 Abth.), V, 1893, pp. 387-428, with pi. 



6. Klaatsch. Hermann. 1S90. Die B. ustflosse dor ( Woptyeygiaer. Fest- 



schr. fiir Gcfjenbaur, Bd. I, pp. 259-391, Taf. I-IV. 



7. Budgett, J. 8. 1902. On the Structure of the Larval Polypterus. 



Trans. Zool. Soc, London, XVI, Pt. VII, October; Works, pp. 154- 

 176, pis. X-XIII, 1907. 



8. Moodie, E. L. 1908. The Lateral Line System in Extinct Amphibia. 



Journ. Morph., XIX, No. 2, 511-540, 17 figs. 



9. Wilder, H. II. 1909. History of the Human Body. New York, Henry 



Holt and Co. Amphibia, pp. 541-2. 



10. Moodie, R. L. 1915. The Sealed Amphibia of the Coal Measures. 



Science, N. S., Vol. XLI, X T o. 1056, pp. 463-464, 1915. 



11. Gregory, W. K. 1913. Crossopterygian Ancestry of the Amphibia. 



Science, N. S., XXXVII, Xo. 960, pp. 806-808. 



391 'Fig. 265. 



