66 



PROCEEDINGS OF THE NATIONAL MUSEUM vol. 79 : ABT. 10 



gate about a certain spot and go down in the crevices among lava 

 rock one or two at a time. It was learned that they went after water, 

 but the question is how they knew it was there. They feed on ber- 

 ries and small fruit and are especially fond of the pricklypear of 

 the cactus. They also get fluid by picking into the cactus pads. 

 Large numbers of their old nests were found but no fresh ones were 

 located. 



CAMARHYNCHUS PROSTHEMELAS Sclater and Salvin 



Black-headed ground finch 



Camarhynchus prosthemelas Sclateb and Salvin, Proc. Zool. Soc. London, 

 November, 1870, p. 325, fig. 4. (Indefatigable Island, Galapagos Arcliipelago.) 



Two females and one juvenile bird with sex not marked were col- 

 lected on Charles Island June 27, 1929. The young bird, which is 

 fully grown, differs from the adults principally in being somewhat 

 browner. The females have the following measurements : Wing, 60.0, 

 60.2; tail, 37.3, 37.5; culmen from base, 10.0, 9.4; tarsus, 21.5, 21.5 

 mm. 



PLATYSPIZA CRASSIROSTRIS (Gould) 



Darvrin's ground finch 



Camarhynchus crassirostris Gould, Proc. Zool. Soc. London, October 3, 1837, 

 p. 6. (Galapagos Islands.) 



Four skins of this species include two females and one with sex not 

 marked from Chatham Island taken July 3 and 4, and August 20, 

 and a male from Academy Bay, Indefatigable Island, July 8, 1929. 



Measurements of these birds are as follows : 



In habits all the ground finches were very much alike, but under 

 observation Platyspiza seemed to be more arboreal and to feed largely 

 on the ovaries and minor parts of flowers, bringing to mind the 

 purple finch. Those collected were taken while feeding on the soft 

 parts of flowers of cotton and agave. 



They appeared to be far less numerous than Geospiza. 



0. S. SOVERNMSNT PR1NTIN5 OFFICE; I9JI 



