Wadsworth.] 
270 
[October 19, 
Tertiary propylite, and, without an exception, that of all 
which follow, behaves exactly like that of the ante-Tertiary dio- 
ritic porphyries, and differently from that of all other Tertiary 
quartziferous rocks , dacites and rhyolites , which only contain 
glass inclusions .” On page 197 [ISTo. 475 (2059)], he again says : 
“ This rhyolitic quartz individual is the only one of the thousands 
and thousands that have been examined with the microscope which 
has been found to bear fluid inclusions .” On page 201 [No. 488 
(2625)] it is said “ that this rock, the only one of this division 
whose doubtless primary quartz bears fluid inclusions , can be 
pronounced a rhyolite by its other petrographical characteristics. 
It properly belongs to the trachytes .” The inconsistency of the 
above statements can be easily seen. The presence of fluid 
cavities in the quartz-propylites is accounted for, even on Zir- 
kel’s statements of where fluid cavities ought to occur, by my 
statements of what these propylites are as given in the prece- 
ding pages. -Regarding the quartz in ISTo. 475 (2059) Zirkel stated : 
u This curious quartz was joined (to) a quite dull and entirely 
decomposed feldspar, like those in granites. . . . The obser- 
ver is permitted to conclude that this singular quartz and the 
adjoining altered feldspar are also foreign inclusions.” This 
might very naturally be the case since the rock is a brecciated one, 
and the part in question is an inclosed fragment of a granite. 
Basalt. 
No. 529 (23) I consider as a diabase both as regards its macro- 
scopic and microscopic characters. 
No. 531 (204) is considered by me to be an old, altered and 
much decomposed andesite (propylite). This, both macroscopic- 
ally and microscopicall , is identical with some of Zirkel’s propy- 
lites, and contains some quartz. Zirkel mistook for “ macroscop- 
ical olivines” some greenish (viriditic) spots arising from the 
alteration of the groundmass in this rock ! Its chemical analysis 
also indicates that it belongs to the andesites. 
No. 534 (263), I claim is a melaphyr, as are Nos. 537 (325) and 
538 (337). The two last contain considerable alteration quartz. 
Nos. 604 (1726) and 605 (1727) are said to be geologically older 
