REPTILIA. 209 
a web between the toes of the hinder feet. The European genus A/yles is 
remarkable for the peculiar habit exhibited by the single species with 
regard to its eggs. When these have been deposited by the female, the 
male takes possession of them, and wrapping them round his body repairs 
to some moist spot, where he remains patiently until they are nearly ready 
to become disclosed, upon which he carries them to the water, this being 
the proper element of the tadpoles. This habit will recall to the mind of 
our reader what has been said of Desmogna*hus. Pelobates fuscus is 
represented in pl. 81, fig. 38ab; Bombinator igneus, in fig. 37ab; both 
European. 
The family of Hylade, known by the dilated toes, is almost entirely 
arboreal in its habits. While the Ranide dwell in the marshes and wet 
places of the earth’s surface, and the Bufonide live on the drier land, the 
Hylade@ are mostly to be sought for among the thick foliage of trees, where 
they make the woods resound with their piping melody. They are espe- 
cially abundant in the dense forests of tropical regions, where they occur 
of various shades of color, among which the green of the leaf and the grey 
of the bark predominate. In the spring of the year they betake themselves 
to the water for the purpose of reproduction ; and the tadpole undergoes 
the same changes which we have described in the case of the true frogs. 
The genera of Hylade, found in North America, are but two. Hyla is 
known by the semi-palmated toes with very decided disks, by means of 
which it can adhere with great tenacity to any surface, even that of glass. 
The slightly emarginated tongue is round or oval. Here belong the well 
known tree frogs, the two best known species of which are HZ. versicolor, 
so similar to the European H. viridis (pl. 90, fig. 6, female, pl. 81, fig. 35, 
male), and H. lateralis. The species H. pickeringit, possibly constituting 
a separate genus, lays its eggs singly on submerged grass, and they develope 
in the very short space of three days. The remaining genus, Acris, has a 
cordiform tongue, and the dilatations of the toes are less conspicuous. The 
species of this genus are not arboreal, being found principally among the 
high grass of marshes and streams. It is among the Bufonide that we are 
to look for the highest development of the anourous batrachian structure. 
Most species are far from presenting that variety of colors, that freshness 
of appearance, and agility of movement, which make the frogs so con- 
spicuous. They are not confined to the vicinity of water, but inhabit 
districts in which but little moisture exists, and remaining concealed 
during the day, emerge at night to gather up such insect food as they may 
chance to come across. Species of the typical genus of this family, Bufo, 
or the toad, although repulsive in their appearance, are yet perfectly 
harmless in themselves, and may be of great benefit to the horticulturist, 
in devouring large numbers of insects injurious to vegetation. A milky 
juice exudes from the skin of most species, secreted by special glands: this, 
in some species, is quite acrid, while in others it is entirely free from any 
such property. A striking difference is observed between the frogs and 
true toads, in the manner in which the ova are laid in the water. In the 
former they appear as amorphous, generally globular masses, enveloped in 
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