Geology and Mineralogy. 75 
in regard to ruptures of various kinds, volcanic cracks, faulting 
and soon. The methods and apparatus are briefly but clearly 
‘described, the text being illustrated by numerous figures. 
7. On a new locality for Xenotime, Monazite, etc., on Manhat- 
tan Island ; by Witt1am Niven. (Communicated.)—The xeno- 
time crystal measured by Mr. H. 8. Washington and announced 
by Mr. W. E. Hidden in this Journal for November, 1888 (vol. 
xxxvi) was found by the writer in a vacant lot at 175th street 
near 10th avenue, New York City, amongst loose blocks of mica 
schist and gneiss which had been dumped there some years before : 
the exact locality, therefore, remained in doubt. Recently, how- 
ever, while prospecting in the extensive excavations for the new 
speedway on the Harlem River I found a number of crystals of 
this interesting mineral in place, also monazite, titanite, epidote, 
beryl, menaccanite and others. 
Prof. A. C. Gill of Cornell University has determined the xeno- 
time by measurement of the angles, finding that they agree to 
within 1’ with those given by Mr. Washington in Mr. Hidden’s 
article, one crystal showing a very narrow pyramid of the 
second order P «(101) in addition to the forms P(111), « P(110) 
and 3P3(311) which were identified by Mr. Washington. This 
face Pa(101) is new to New York xenotime, although observed 
elsewhere. The most interesting crystal showed an abnormal 
development along the vertical axis producing a prismatic form 
like that common in zircon, while in close proximity to it was a 
crystal of the ordinary habit. The monazites were usually found 
in close association with the xenotimes. All were well defined 
crystals, and one was exactly of the habit shown in figure 2, page 
750, Dana’s System of Mineralogy, sixth edition, as occurring at 
Watertown, Conn. 
The titanites have a remarkable resemblance to those from 
Tyrol and were usually about 12™™ in size, one crystal measured 
fully 40™™ and some fragments were transparent. A surface of 
the schist over 20° by 28° in size showed more than 40 yellow- 
ish green crystals. 
The xenotimes and monazites were mostly embedded in oligo- 
clase near a coarse granite vein at 185th street and Harlem River 
and were associated with menaccanite, while the titanite and 
epidote occur in a chloritic mica schist at 167th street and Harlem 
River. My thanks are due to Prof. A. C. Gill for identifying and 
measuring the crystals. 
8. Brief notices of some recently described minerals.—Lawson- 
ITE, named after Prof. A. C. Lawson, is a new rock-forming 
mineral described by F. Leslie Ransome, from the crystalline 
schist of the Tiburon Peninsula, Marin County, California ; also 
occurring in larger crystals embedded in a micaceous mineral de- 
termined as margarite in veins in the schist. It forms crystals of 
prismatic habit belonging to the orthorhombic system : prismatic 
angle 67° 16’; cleavage perfect parallel to 4 and less so parallel 
to ¢; crystals colorless to pale blue ; hardness about 8 ; specific 
gravity 3°084. An analysis gave: 
