2 University of Michiyan 



The Santa ^larta specimens are both females bearing eggs, 

 and they were found in similar situations — on the steep bank 

 of a mountain stream at an altitude of 4,500 feet on the moun- 

 tain of San Lorenzo. One was in a niche in the rock about 

 ten feet above the water, the other was in a hollow in a bank 

 of earth about seventy-five feet above the stream (Fig. Ci). 



One of the females taken was found on July 13. and car- 

 ried on the back twenty-eight pale yellow eggs, in each of 

 which the embryo can be easily distinguished as a dark 

 streak lying in a deep groove in the enormous yolk ( Figs. 4 

 and 7). These embryos have the bead, limb buds and tail 

 differentiated, the tail being short and filamentous in form. ( )n 

 each side of the neck a large gill membrane arises and is 

 spread over the anterior quarter of the egg, the two mem- 

 branes together covering practically the anterior half of each 

 ovum (Fig. 2). 



The embryos on the second female (Fig. 5). taken on 

 July 22, twenty-one in number, had reached the time of hatch- 

 ing and during the ensuing forty-eight hours the young were 

 observed to leave the Qgg. During this time the young frogs 

 struggled about within the egg memljranes at intervals, and 

 tlirough these struggles each finally ruptured the memlu-ane and 

 thrust its head through the rent. They did not at once leave the 

 nurse, but remained upon her back, the hind limbs enveloped in 

 the ruptured membranes. Within one or two hours after hatch- 

 ing, two or three of the young had left the nurse, l)ut wliether 

 vohmtarily or owing to the movement of the nurse was not 

 determined. 



The young frogs at the time of hatching (Figs, i and 3), 

 do not have even a rudiment of tail, are about 10 mm. in length. 



