484 ZOOLOGY. 



usually toothless. The larva3 are called tadpoles, and repre- 

 sent the permanent, adult form of the perennibranchiate 

 Lhodela. 



Among the lower frogs or arciferons Anura of Cope, i.e., 

 those with the acromial and corocoid bones divergent and 

 connected by distinct cartilage plates, are certain forms, 

 as Alijtes, Pelohates, and Pelodytes, whose breeding habits 

 are peculiar and interesting. The eggs of Pelodytes are 

 deposited in small clusters in the water, those of Pelo- 

 hates in a thick loop. The male of the European Alytes 

 ohstetricans winds a string of eggs which it takes from 

 the female, and goes into the water, where it remains 

 until the young (which have no gills) are hatched. The 

 American Scapliiopus, or spade-footed toad, is not known to 

 have this obstetrical habit. This singular toad appears sud- 

 denly and in great numbers. It remains but a day or 

 two in the water, where it lays its eggs in bunches from 

 one to three inches in diameter. The tadj)oles hatch 

 in about six days after the eggs are laid ; their growth is 

 rajiid, the young toads leaving the water in two or tliree 

 weeks. The croaking of this toad is harsh, peculiar, and 

 need not be confounded with that of any other species. 

 (Putnam.) As the spcde-footed toads are rarely seen, it is 

 possible that they burrow in the soil, like the European 

 Alytes. Another peculiarity in the reproductive habits of 

 Alytes, Pelohates, Gultrijies, and Pelodytes is that they 

 spawn at two seasons instead of one, and that their larvas, 

 like Pseudes (Fig. 437), attain a greater size than those of 

 other frogs before completing their metamorphosis. (Cope.) 



Among the tree-toads, Polypedafes of tropical Western 

 Africa, contrary to the usual habits of frogs, deposits its eggs 

 in a mass of jelly attached to the leaves of trees which bor- 

 der the shore overhanging a pond. On the arrival of the 

 rainy season, the eggs become washed into the pond below, 

 where the male frog fertilizes them. Our common j)iping 

 tree-toad {Hyla Pickeringii Le C'onte), about the middle of 

 April, in the neighborhood of Boston, attaches her eggs 

 simply to aquatic jplants. The young are hatched in about 

 twelve days. 



