53 mnetep:n']'h report. 



true of the amphibians than of the reptiles^ for the former have a greater 

 capacity for enduring the cold." 



These statements of distribution are also applicable to the Douglas 

 Lake fauna, although the capacity to endure cold may not be the only 

 difference between the amphibian and reptilian species which should be 

 considered in this connection. The amphibian faunas of the Northern 

 Peninsula, the Douglas Lake region and the Saginaw Bay region are 

 essentially tlie same, and excepting one species, the mink frog, Rana 

 septentrionalis , all of the species of amphibia known to occur in these 

 tliree regions are found soutli of the Saginaw-Grand line. The Douglas 

 Lake region marks the nortliern limit of the known distribution in 

 Michigan of but a single amphibian species, Acris gry litis, the cricket 

 frog, although there are species whose known northern limit is south 

 of this region. The reptilian faunas of the three regions compared are 

 not the same, the fauna of the Douglas Lake region including more 

 species than the fauna of the Nortliern Peninsula and less than that of 

 the Saginaw Bay region: Six of the 12 species of reptiles found in the 

 Douglas Lake region, at present are not known to occur north of the 

 Douglas Lake region in Michigan. These species are Eumeces quiti- 

 quilineatus, Heterodon platyrhinos, Lnvipropeltis doliatus trianguhis, 

 Thamnophis sauritns, Chrysemys cinerea and Terrapene Carolina. 



Comparing the amjjhibian and reptilian faunas of the Douglas Lake 

 region with those of INIichigan as a whole, as regards specific composition, 

 the amphibian fauna of the Douglas Lake region will be found richer 

 than its reptilian fauna, botli in relative number of species and kinds of 

 species. The amphibian fauna of this region includes about two- 

 thirds of the species of amphibians reported from Michigan and rep- 

 resentatives of each amphibian family found in the state. The reptilian 

 fauna of the Douglas Lake region, however, includes less than half of 

 the reptilian species known to occur in Michigan, and is essentiall}' 

 ophidian, two of the three turtles, Chelydra serpentina and Terrapene 

 Carolina, and the single lizard, Eumeces quinquilineatus being rare in tlie 

 region. Of the 16 species of snakes reported from Michigan (Ruthven, 

 Tliompson and Thompson, 1912), 12 are found in the Saginaw Bay 

 region, eight in tlie Douglas Lake region and six in the Northern Penin- 

 sula. This scant snake fauna of the Douglas Lake region is composed 

 of small, or at most moderately large species, feeding almost entirely 

 upon fishes, amphibian and small invertebrates. Two types of snakes are 

 (•()ns])icuously wanting among these eight species, namely, species feeding 



