242 U. S. NATIONAL MUSEUM BULLETIN 206 



The eggs of Crossodactylus gaudichaudii, apparently laid under leaves 

 in water, have never been found, only the young tadpoles already 

 swimming. 



The adults have a very high call, pip-pip-pip-pip like that of a 

 small chicken, but more rapid. They are found on leaves and under 

 stones in mountain streams everywhere near the city of Rio de Janeiro, 

 often associated with the tall semiaquatic plants called liros. 



In the more than a hundred individuals of the four species which 

 have served as the basis for these notes, some very interesting facts 

 were observed in regard to the spines on the first finger (see table 1). 

 In the 44 examples of gaudichaudii from Covanca, very young ones 

 measurmg only 13 to 15 mm. and with vestiges of the tail still unab- 

 sorbed showed one or two small black-tipped spines. At 18 mm. of 

 length, three spines were often present, two in the group being larger 

 and better-developed than the last which was just making its appear- 

 ance. At 19 mm. four spines unequally developed were sometimes 

 present. At 22 mm. five spines first appear, and no individuals under 

 26 mm. had the maximum number of six spines. About 16 percent of 

 all individuals completely lacked the spines, without regard to size. 

 Other frogs from other localities bear out these findings. 



The series from localities near Teres6polis, supposedly representing 

 aeneus, while having no very young individuals, shows in half -grown 

 ones and adults the same correlation as to size and number of hand 

 spines. None of the 26 had as many as six spines. Five spines, how- 

 ever, were not found in specimens measuring less than 26 mm., four 

 spines occurred down to 24 mm., and three down to 18 mm. 



The same observations hold good for the species supposed to have 

 fewer spines, dispar (of which 28 examples, including thi-ee^cotypes, 

 are at hand) and trachy stoma (26 examples) . 



The outer layer of the spine is apparently shed regularly at times, 

 for in a few individuals which had fragments of loosened skin on the 

 hands, the black coverings from the entire patch of spines could be 

 lifted off with the skin, leaving the new spines as black and sharp as 

 before. 



Another peculiar characteristic of most males is the possession of a 

 row of small spines, sometimes black-tipped, around the outer edge 

 of the upper lip. They are evenly spaced, forming a single row almost 

 concealed when the mouth is closed. Most frequently these spines 

 are not black, being the same as the lips in color; in these cases they 

 are hard to see, as they are almost microscopic in size. In the females 

 the lip is either smooth or has a row of small spicules. In some 

 males the spicules are equally poorly developed. 



