102 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 



ENGYSTOMATIDAE. 

 13. Atelopus gracilis, sp. nov. 



Types. — Mus. Comp. Zool., No. 2,423, Gorgona Island. Fourteen specimens, 

 adults and juv. 



Rather similar to A. flavescens Dum. and Bibr., the dij];ital arrangements are 

 the same. This island race, however, differs in the following points. First, 

 the head is contained three tinges in the length of the trunk of an adult female, 

 and two and one half times in an adult male. Secondly, the tibio-tarsal ar- 

 ticulation reaches slightly beyond the anterior border of the eye. The color is 

 very deep brown, with red-brown longitudinal stripes. In many examples 

 there is a white lateral stripe running from the posterior border of the eye to 

 the groin. 



