BATllACIIIA. 



337 



TTnited States is the JL nrslcolor, nml tlu> cDiiiiiinii :in.l only E\iroiK'.an speoiis i>! the 

 jr. arhorea. 



The Ilyhv. of North Anierica lay their Ci^gs in the water, on some fixed liody, as an 

 aquatic plant, in smaller packets than those of the frogs, and not in strings, as do the 

 toads. The youni^ of the IF. versicolor are gray, and they undergo their metamor- 

 phoses while small. 



The Hylella j:>lat)jce2^hala of southern Mexico is said to deposit its eggs in the water 

 which accumulates in the axils of the leaves of certain plants of the genus Tillnndsia, 

 and to undergo its metamorphosis high above the ground. Tiie species of Xoto- 

 trema and Opisthode!j}k>/s have another method of carrying their eggs. They place 

 them on their back, and in a pocket formed by the infolding of the dorsal skin. 

 This is forced upwards from a point on the coccyx, in the manner of the finger of a 

 o-love, and expands so as to cover, when distended with eggs, almost the whole dorsal 

 region, see Fig. 191. In JVbto- 

 trema inarsupinUim of Peru, 

 the young leave the pouch 

 w-hile tadpoles. In i\r. testiir 

 dineum and in Opist/wdclphj/fi 

 ovifera, they pass through 

 their entire metamorphosis in 

 this singular position. In the 

 latter species the branchis of 

 the larvae arc of a peculiar 

 bell-shape. 



The species of Hylidse are 

 noted for their loud and varied 

 voices. The first note of 

 spring in the United States 

 is the shrill piping of the 

 Ilyla pickeriiigii in the 

 swamps. If these little ani- 

 mals are imprisoned at this ' i' ■ -"i. ' 

 time in a vessel, the deafeiiing 



loudness of their voice can be ajjpreciated. Near the same time liie ralllu of the 

 Acris gryllus is heard from the same localities. A similar but weaker sound can be 

 produced by violently rattling clay-stone pebbles together. Later in the season, in 

 similar localities of a generally more sandy character, the voice of the Heloicetes triseria- 

 (lis is heard. The note of this frog may, in fact, be heard all summer in swampy ground, 

 which it never leaves for the trees. It may be imitated by scraping a coarse toothed 

 comb, and at the same time lifting it from some confined space, as of a pitcher, to its 

 mouth. It is, in other words, a rattle with a rising inflection at the end, more delib- 

 erately uttered than that of Acris crejntans. In the spring, especially when it rains, 

 the country is vocal in the evening with the clear, loud, trilled rattle of the Ilyln 

 versicolor. This species also continues its vocaliz.ation at intervals through the 

 summer, mostly in the evening. The Acris and Heloecetes may be heard during the 

 day as well. In the autumn the tree-frog that is most frequently heard is Hyla 

 pickeringii. Its voice is less vivacious than in the spring, and its lonely pipe m 

 dry woodlands is' always associated with golden-rods and asters and falling leaves, 

 vol.. III. — 22 



