Occasional Papers of the Museum of Zoology 7 



strongly spotted with creamy white ; the tip may be creamy white 

 with a dark band just behind it, and occasionally these light 

 spots are rose or flame color. The tadpoles with the latter colora- 

 tion are very conspicuous in the water. 



The body is perfectly round; the tail is unusually long (even 

 tadpoles with legs so well developed that they could hop about 

 on land had tails twice as long as the body) ; the muscular portion 

 of the tail is so wide that the crests are not conspicuous, and the 

 latter are so pigmented that they are not translucent. When the 

 animal is alive the crests are thickly covered with protruding pores 

 which have the appearance of tiny tubercles. Three very striking 

 characters, the dentition, and the positions of the spiraculum and 

 anus, distinguish this tadpole from other known American forms. 

 The mouth is very large and almost round. The upper beak is 

 black edged with white, and there is no horny beak on the lower 

 lip. The teeth are in 2-3 ridges above and 7-8-9-10 below; the 

 upper series bear more than one row of teeth on each ridge. Below 

 the first lower series there are often several ridges which either 

 have no teeth or scattered patches of very small ones. The 

 spiracvdum is median, very inconspicuous, and is either just caudad 

 to the lower lip or concealed beneath it. The median anal open- 

 ing is concealed under the tip of a prominent flap which is attached 

 to the body at its base and to the tail by a thin membrane. 



m 



Description or the Tadpole 



The following detailed description of the tadpole has been 

 prepared from specimen No. 53892, Museum of Zoology, Uni- 

 versity of Michigan; collected from Laundry Creek on June 25, 

 1919. 



Length of body once and three-fourths its width and one-half 

 the width of the tail; nostrils protruding, much nearer the eyes 

 than the end of the snout, their distance from the eyes equal to 

 the diameter of the latter; eyes small, on upper surface of the body, 



