294 FieLp CoLumBian MuszEuM—GEo_oecy, VoL. I. 
zonal growths with chromite which also occurs alone, widely distributed 
inthe stone. The little grains of the latter mineral appear brown, 
translucent. Also pyrrhotite (magnetkies) is present in considerable 
quantity and generally in large individuals. The structure of the 
whole stone indicates a cooling from a fused liquid, a view also sup- 
ported by the porphyritic crystals of chrysolite and the skeletons of 
bronzite in the colorless base. There is no trace of breccia structure 
and the occurrence of few well-defined chondri gives no further proof. 
As has been often observed in meteorites, the whole stone has much 
more the character of a suddenly cooled mass, a character which is 
also indicated by the undulatory extinction of the chrysolite, the 
skeleton growths of pyroxene and the sudden variations in composi- 
tion. The Long Island meteorite in mineralogical characters belongs 
to the harzburgites. If among terrestrial rocks we look for masses 
which in a structural and mineralogical way can be compared to the 
Long Island meteorite, it will be found that the number is a very 
limited one for the reason that rocks of similar composition have suf- 
fered in most cases much decomposition, by which their structure 
becomes indeterminable. But at all events it seems probable from 
the few observations on, for example, the terrestrial basalts of Green- 
land, that similar structures as they are here observed and in many 
other meteorites are formations characteristic of cooled rocks in which 
silicate of magnesia plays an important part, and that no grounds are 
given for the belief that formations of this kind in any of the terres- 
trial rocks have originated in any different way.” 
To the observations of Weinschenk there is little of importance 
to be added. The crystalline structure is perhaps hardly as promi- 
nent megascopically as one would judge from Weinschenk’s account, 
~while the chondritic structure is easily recognized in all the sections I 
have examined. There are numerous polysomatic porphyritic chry- 
solite chondri and typical fibrous ones of enstatite. One of the latter 
observed was 2.5 mm. in diameter and it is evidently not cut through 
its center. <A black, seemingly carbonaceous matter, borders its outer 
edge. The fibers are minute and lie in parallel groups extending in 
various directions. A porphyritic chrysolite chondrus seen had a 
diameter of 1.25 mm.,a single grain reaching the size of .025 mm. 
Another monosomatic chrysolite chondrus seen was made up of chrys- 
olite porphyritically developed in glass and witha distinct circular 
border of chrysolite all extinguishing simultaneously. This chondrus 
also contained a large grain of troilite. The crystal outlines of the 
chrysolite individuals whether developed in the chondri or out are 
often well defined, the predominant habit being short stout crystals 
