Occasional Papers of the Museum of Zoology 5 



but two distinct songs were heard, the sustained trill of B. 

 aiuericanus and the "'metallic droning sound, not conspicuously 

 vibrated"" (Dickerson, loc. cit., p. 95) characteristic of B. 

 foidcri. The latter was traced to a specimen of the form 

 which resembles B. fozvleri. 



These studies apparently show that there are two forms of 

 the genus Bufo in western Michigan ; one with the characters 

 of Bufo amcricauus ; the other in structure, color and song 

 indistinguishable from Bufo foidcri. Furthermore a com- 

 parison of specnnens of the latter form with one of the original 

 specimens'^ of Bufo foideri, from Danvers, Massachusetts, 

 reveals no differences except that the cranial crests in the 

 eastern specimens are closer together. It is planned to study 

 the forms in the breeding season to ascertain if there are 

 differences in the breeding habits, and if the difference in the 

 voice is constant. 



'* Cat. No. 50246, MuseuiTi_ of Zoology, University of Michigan ; formerly Cat. 

 No. 518, Museum of Comparative Zoology. 



