440 J. E. Whitfield — New Meteorite from Mexico. 



The composition of the metallic portiou does not differ 

 materially from that of other meteorite irons as the following 

 analysis will show. 



Fe._ _ 91-48 



Ni 7-92 



Co 0-22 



P 0-21 



S -. 0-21 



C 0-06 



100-10 



A feature of the meteorite is the presence of large, deep 

 pittings on one side ; these are a little greater in diameter just 

 below than immediately at the surface and each one has a 

 little substance left at the bottom, which evidently is the re- 

 mains of what originally filled the cavities. I succeeded in 

 breaking from the bottom of one pitting material sufficient to 

 determine its nature. It proved to be troilite as the analysis 

 will show. 



NiS 2-13, FeS 85-27, Fe 9-37. 



The exposed surface of the troilite was greatly decomposed ; 

 this portion gave by analysis the following figures. 



NiS 2-07, FeS 37-51, Fe a O s 37-80, Moisture =19-85. 



This decomposition gives grounds for the idea that the deep 

 pittings were formed by the removal of troilite nodules, partly 

 while the mass was hot and partly by the subsequent weather- 

 ing. 



There are nodules of troilite throughout the entire mass of 

 the meteorite but none are removed, so as to form pittings, on 

 any other part of the surface but the side which is supposed to 

 have been the front. 



The mass is deeply furrowed, as may be seen to some extent 

 in the figure, and all the furrows tend away from the side 

 containing the pittings. 



Slices of the meteorite, when etched, show rather coarse 

 Widmanstattian figures and also dark diagonal bands of troi- 

 lite. 



From the locality in which this meteorite was found it is but 

 proper that it should be called " La Bella Roca.'' 



I am indebted to Messrs. Ward and Howell for the material 

 for examination and the privilege of description. 



Chemical Laboratory, U. S. G-eol. Survey, 

 Washington, D. C, March 3d, 1889. 



