AMPHIBIANS. 59 



Hahits and Haliitat-: The iioi'therii or liiiiik frog is distinctly 

 aquatic. It has been said not to freqnent lakes or ponds, but in the 

 Northern Peninsula Ruthven (1910) has found it more character- 

 istic of the inland lakes than of the streams. Wlion frightened, it 

 stays for a long time under water. It is solitary in habits, and 

 never stravs far from the shores of the rivers and lakes. The food 

 consists of water insects and small fish. The eggs of this frog are 

 laid in June and July, and are attached to water plants. Two 

 years are required for the full development and metamorphosis 

 (Dickerson, 190G, p. 225). When annoyed it gives otf a strong 

 musky odor, somewhat resembling that of the mink, and because 

 of this odor it is frequently called the ''mink frog.'' 



Dlstrihution: Adirondack Mountains to ^linnesota and Ontario. 

 (Dickerson, 190G.) 



Michigan : Specimens in the University Museum from Keweenaw 

 (Isle Royale), Ontonagon, Houghton and Dickinson Counties. Re- 

 l^orted from Ontonagon and Marquette Counties (Ruthven, 1906) ; 

 Keweenaw County (Isle Romaic) (Ruthven, 1909) ; Dickinson 

 County (Ruthven, 1910). 



RANA CATESBEAXA Shaw. 



COMMON BULLFROG. 



Description: Body large and stout, head broad. Eyes large and 

 prominent. Ear of male larger than eye. Glandular fold from eye 

 to arm, curving behind ear. Xo lateral folds. P>ack and under 

 surface slightly granular. Feet webbed, leaving last joint of fourtli 

 toe free. Inner sole tubercle distinct. 



Ground color greenish brown, sometimes spotted with darker. 

 Limbs spotted or barred. Under surface j^ellowish white, usually 

 mottled with darker. 



Jlfeasurements: Specimen No. JjOOIS. 



Length of head and body 130 



Length of hind limb to heel 098 



Width of head 017 



Hahits and Hahitat: liana catcsJjcana, the connnon bullfrog, is 

 the largest of our frogs. It does not al'ways follow, however, that 

 the individual I*, catesheami is larger than the individual R. clam- 

 itans or R. piplens, since the size depends upon the food and en- 

 vironment. The bullfrog is aquatic in its habits, being found during 

 the summer in large ponds or lakes, usually those with mud bottoms 



