NOTES ON BATBAOHTANS OF THE PARAGUAYAN CHACO. 809 



VI. Paludicola fuscomaculata, Steindachner. 



This is the largest of the genus that I found in the Chaco. 

 It is a short-limbed frog, with spreading slender toes and small 

 head. 



The upper surface is marked with characteristic marblings, 

 which vary, however, greatly in colour. The metatarsal tu- 

 bercles are large, horny, shovel-shaped, and black. 



The peculiar cry which is so constantly heard in the neigh- 

 bourhood of shallow pools, and resembles that of a kitten, is 

 produced by the alternate inflation of throat and abdomen. 



When fully inflated the frog appears to be the size of a golf 

 ball, but, if startled, instantaneously shrinks to one fifth of 

 that size, so that it seems to have vanished. It has also the 

 power of ventriloquising. 



In the spawning time it was found at night floating on the 

 surface of pools in the distended condition, and crying to the 

 females in a most mournful way. On coming to the surface it 

 fills its lungs with a few gasps, greatly distending the walls of 

 the abdomen, and then drives the air into the throat diver- 

 ticula of the pharynx, causing them to become distended as the 

 stomach collapses, and giving rise to a kitten-like cry. 



The eggs are chiefly laid in January, and are found em- 

 bedded in a frothy mass floating upon the surface of the water. 

 The eggs themselves measure 1 mm. in diameter, and are 

 without pigment and with extremely little yolk. They become 

 free-swimming within from eighteen to twenty-four hours of 

 the time of the first segmentation. When ready for hatching 

 they wriggle their way through the froth to the water below, 

 and hang into it from the floating froth. 



In this rapidly hatching, free-swimming larva many of the 

 processes of development are blurred, and as it were hurried 

 over. The external gills never reach a high state of develop- 

 ment. The cell layers are many cells deep and diff'use, and the 

 involutions and evolutions are difficult to follow. 



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