2 14 



ANURA 



tadpole is nearly ready to leave the water, its whole bulk is re- 

 duced to less than one-fifth that of the largest tadpole. It measures 

 from snout to vent only 1|- inch (in the 7-inch tadpole this 

 distance is fully 2 inches), and the tail, devoid of fins, is 

 reduced to 2 inches in length. Instead of the solitary left 

 spiracle there are now two, one on the ventral side and a little 

 in front of the base of each arm, the border of each hole being 

 continued by a peculiar semilunar fold. 



Hylodes. — The numerous species, nearly fifty, of this tropical 

 American genus exhibit several anatomical differences. The 



tympanum is sometimes indistinct 

 or hidden, in which case the 

 Eustachian tubes are generally 

 very narrow. The fingers are free, 

 and carry discs, like the toes, 

 which are sometimes slightly 

 webbed. The males have a sub- 

 gular vocal sac, producing a loud, 

 or whistling, voice. The general 

 appearance is that of land- and 

 tree-frogs ; the size is small, mostly 

 between 1 and 2 inches. 



H. martinicensis is about 1-|- 

 inch in length. The ground- 

 colour is pale yellow -grey, with a 



Fig. 42. — Hylodes martinicensis. 



an egg with embryo about seven large brown patch On the nape, 



days old ; 2, another, twelve days t_ • , , . . 



old; 3, the young Frog just hatched; Which colour IS Continued over the 



Peters*)' ^' '"'"" ""'^ "" ^' ^'^""' '^*°^^ "^ *^® ^^^^^ °^ ^"""'^ ^'^ ^^^^ 



coherent or dissolved patches. A 

 dark brown stripe runs along the middle of the sides. The 

 limbs are barred with brown, the under parts are whitish. This 

 species, known by the vernacular name of" coqui," inhabits many of 

 the West Indian islands, e.g. Barbadoes, Martinique, Porto Eico, and 

 Hayti. It has become famous, as it was the first instance known 

 of a frog which undergoes its whole metamorphosis within the 

 egg. The pairing takes place on land, in the months of May 

 and June, when the female lays about twenty eggs, which are 

 enveloped in a foamy mass and glued on to a broad leaf, or 

 hidden in the axillae of Iridaceous plants. The mother seems to 

 remain in the neighbourhood watching the eggs, which are. 



