Merrill.] 
462 
[April 5, 
istic angite forms ( ooP, oo Pro , oo Poo ) I think there can be no 
doubt that they are old augites and not hornblendes. 
Mr. Wadsworth regards the quartz propylites of Zirkel’s 
Report, Nos. 228 and 229 as being the same as certain rocks called 
in the same Report granite porphyries, 1 and I agree with Mr. 
Wadsworth as to ISTo. 228. It much resembles the specimen No. 
122 under granite porphyries. In both are titanites, and in both 
there appear to exist similar relations between the titanite and 
the hornblende. The hornblendes in both have the same staff- 
like structure. 2 
No. 226 is so much altered that I find a diagnosis based solely 
upon lithological evidence difficult. 
No. 227 Mr. Wadsworth regards as an old, decomposed, frag- 
mental rock. 3 This rock is also much altered. Professor Zirkel 
in his Report mentions that the quartz has fluid, but no glass, 
inclusions. In one quartz I found a large glass inclusion. 4 
Nos. 230 and 231 Mr. Wadsworth regards as altered andesites 
containing alteration quartz. 5 I think that the quartz in the 
groundmass of No. 230 is secondary. No. 231 seems to me to be 
a fair propylite in the sense of that term adopted in Zirkel’s 
Report. 
The Report mentions an andesite (p. 122) from the first hill 
north of Gold Hill Peak, Washoe, as containing no quartz, but 
Mr. Wadsworth found quartz in “ com paratively large amounts.” 6 
No number is mentioned in the Report for this sjiecimen, but the 
thin section bearing the quotation of the locality on its label is 
numbered 233 (a). I think that some of the hornblende has 
altered further than to the stage of the greenish product men- 
tioned in the Report, and has given rise to some secondary sili- 
ceous deposits of apparently hyalitic nature ; opalitic and hyalitic 
1 These Proceedings, Vol. xxi, p. 264. 
2 It appeared to me that, of the feldspars, plagioclase predominated in all three of 
these sections; perhaps, on purely lithological evidence, I should have taken these to 
be dioritic porphyrites. 
3 These Proceedings, Vol. xxi, p. 264. 
4 This glass inclusion was in a quartz near to the end of the slide bearing the “collec- 
tion number.” 
5 Ibid., p. 264. 
6 Ibid., p. 265. 
