1884. ] Batrachology in the years 1880-188}. 151 
her observations upon the metamorphoses of Hyla versicolor. 
Eggs laid May roth become frogs on July 4th. In two days after 
deposition all the ova were hatched, in four days the external gills 
were developed, in eight days the external gills were completely 
resorbed on both sides ; and in seventeen days after deposition the 
hind legs commenced to bud, but the fore-legs did not both he- 
come free until about July 3d, by which time the edges of the tail 
were undergoing resorption. The tail in some cases disappeared 
in thirty-six hours. 
Miss Hinckley also describes and figures (Proc. Bost. Soc. Nat. 
Hist., 1882, pp. 307-315) some differences in the mouth structure 
of the anurous batrachia of Massachusetts. These fall into three 
groups, which characterize the frogs, tree-frogs and toads. In 
the first the upper lip is shorter and narrower than in the others, 
and a papillose border, bending inwards at the angles of the 
mouth extends around the lower lip and overlaps the upper 
slightly on both sides. 
In the tree-frog tadpoles observed (Hyla versicolor and Hyla 
pickeringit) the upper lip is broad and falls into two deep curves, | 
along the lateral portions of which extend papillz like those of 
the lower lip. The papillze are small, and the papillose border 
does not bend inwards at the mouth angles. In the toads, Bufo 
americanus and B. fowleri, the upper lip is broad and nearly 
Straight, and the lower lip is fringed and without papillz in the 
the center, | 
The upper lips in all the species, the under lips when not edged 
with papillz, and several fleshy folds which extend across both 
lips, especially the lower, are fringed with what appear in the 
Microscope to be closely set teeth of unevenlength. These fringes 
Serve to collect and hold the food, both upper and under lips being 
Used for this purpose; and Miss Hinckley observes that animal 
food appears to be preferred to vegetable by young tadpoles. Rana 
Plvatica has four fringed folds on the lower lip, while the other 
anidæ observed have three. Hyla versicolor has three fringed 
folds on the lower lip, while Hy/a pickeringit has but two, and 
à short space of fringe on the margin of the lip. The same ob- 
w has also some notes on the development of Rana sylvatica 
“gig many respects appears to be very distinct from other 
v England Ranidæ. It congregates earliest in spring for the 
ee Of oviposition, but cannot move in water below 45°F. 
