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AMERICAN NATURALIST 
VOR: XXXIII. September, 18909. ° No. 393. 
A CONTRIBUTION TO THE LIFE HISTORY OF 
AUTODAX LUGUBRIS HALLOW. A CALI- 
FORNIAN SALAMANDER. 
WM. E. RITTER AND LOYE MILLER. 
AUTODAX is a genus of salamanders confined, according to 
our present knowledge, to western North America and almost 
entirely to California. Three species are known, namely, A. 
lugubris Hallow., A. ferreus Cope, and A. zécanus Cope. The 
genus belongs to the Plethodontidæ and is undoubtedly close 
of kin to Plethodon itself. A. Zugubris, the most common and 
best known of the species, is, however, according to Cope ('89), 
“one of the most marked species of North American sala- 
manders,” and it is an interesting and suggestive fact that all 
the zodlogists who have written concerning members of the 
genus have noted about them various reptilian characteristics 
either of structure or habit. Thus, Spencer Baird ('52), one of 
the earliest observers of A. /ugudris, the subject of the present 
paper, mentions the unusual size of the teeth and compares the 
undulating outline of the mouth to the mouth of the alligator ; 
and Charles Girard ('58) makes the same comparison. Cope 
(89) points out these reptilian assimilations in the following 
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