No. 401.] REVIEWS OF RECENT LITERATURE. 455 
With this syenite are also associated a biotite and a hornblende- 
syenite and a hornblende-granite. The major portion of the trap 
mass is a fine-grained hypersthene-gabbro. The relation of the 
syenites to the trap could not be discovered. 
Notes. — The granite-gneiss near Middletown, on the Connecticut 
River, is, according to Westgate,’ an igneous rock. The rock is a 
biotite gneiss, often containing eyes of feldspar consisting of cores 
of single orthoclase crystals enclosing grains of other feldspars, and 
sometimes surrounded by peripheral zones of a granular feldspar. 
A second series of analyses of Italian volcanic rocks is presented 
by Washington. Among them is an analysis of ciminite from La 
Colonetta, on the south slope of Monte Cimino; one of the “ mica- 
trachyte," or selagite, from Monte Catini, Tuscany ; one of an ande- 
site from Radicofani, Tuscany, and one of the well-known leucitite of 
Capo di Bove. The analyses of the ciminite (I), the selagite (II), 
and the leucitite (III), follow: 
SiO; TiO, AlO; FeO FeO MgO CaO BaO NaO K,O H,O Tot. 
57.31 40 14.71 I.21 4-37 7:80 6.90 1.35 6.38 .18 = 100.61 
56.39 2.07 - 1488. 336 354. 7:83 4.06 L30. 784 1.33 = 9960 
45-99 +37 17.12 4.17 5.38 5.30 10.47 .25 2.18 8.97 .45 = 100.65 
The ciminite analysis differs from the original analysis of Washing- 
ton's type rock in showing less Al;O; and more MgO. The difference 
in the two analyses i is explained as due to incomplete separation of 
the two oxides in the earlier analysis. The selagite appears to be 
a minette-like form of ciminite, differing from the latter in possessing 
biotite in place of olivine and orthoclase. 
An excellent description of the titaniferous iron ores of the Adi- 
rondacks appears from the pen of J. F. Kemp.’ The ores are shown 
to contain small quantities of hypérsthene, augite, plagioclase, and 
many of the other constituents of gabbros. From their close asso- 
ciation with rocks of this class, the author regards the ores as dif- 
ferentiation products of their magmas, in the same way that the 
titaniferous ores of Minnesota, of Sweden and Norway, and of other 
places are believed to be varietal phases of a similar magma. Inci- 
dentally, the paper describes a few gabbros and anorthosites from 
near Lake Sandford, in Newcomb township. 
1 oe of Geol., vol. vii, 1899, p. es 
mer. Journ. Sci., vol. ix, 1900, p. 4 
Seeds Ann. Rept. U. S. Geol. fp Pt. in, p. 377. 
