Geology and Mineralogy. 243 



brown to dark grayish brown color. Specific gravity 3*493, 

 hardness o'o to 6. The crystals are opaque and under the micro- 

 scope are seen to have a pseudomorph-like structure consisting of 

 a complex yellow substance of strong double refraction and a 

 colorless one feebly birefringent. An analysis by Chr. Christen- 

 sen yielded : 



Si0 2 P 2 5 (Ce, La, Di) 2 3 Th0 2 A1 2 3 CaO Na 2 H 2 

 15-12 17-78 40*51 3-26 9*28 1'81 5*63 6'28 = 99*67 



The formula of the mineral is doubtful because of the altera- 

 tion it has undergone. Erikite is named after Erik the Red, who 

 discovered Greenland in 986. The same author gives a further 

 description of the rare species schizolite (see this Journal, x, 325, 

 1900), first described by Winther from the same region in Green- 

 land. It is shown to be triclinic in crystallization and nearly 

 similar in form to pectolite and wollastonite; it is also related to 

 rhodonite and babingtonite. — Medd. om Gronland, xxvi, 1903. 



Cktolithionite is a new fluoride of aluminium, sodium and 

 lithium described by N.-V. Ussing from the cryolite locality at 

 Ivigtut, Greenland. It occurs in large dodecahedral crystals 

 which are colorless and show distinct dodecahedral cleavage. The 

 hardness is 2*5 to 3 and the specific gravity 2 '77 7. An analysis 

 of purified material gave : 



F 60-79 Al 14-46 Na 18-83 Li 5-35 ign 0*36 = 99*79 

 This leads to the formula LigNa^A^F^, which corresponds to a 

 cryolite with half the sodium replaced by lithium. — Bull. Acad. 

 Sci. JLettr. Danemark, No. 1, 1904. 



Thorianite is a new radio-active species from the gem wash- 

 ings at Balangoda, Ceylon, named by W. Dunstan ; it has also 

 been observed in pegmatite at Gampola, Ceylon. It occurs in 

 black cubical crystals of specific gravity 9 32. An analysis by 

 G. S. Blake gave the following results : 

 Th0 2 (Ce, La, Di) 2 3 UO, Zr0 2 Fe 2 3 PbO Si0 2 

 76-22 8*04 ' 12-33 tr 0'35 2*87 0-12 = 99-93 



The same mineral has been examined by W. Ramsay as to its 

 radio-activity and chemical composition, with results in the latter 

 direction that do not agree with the analysis above quoted. — 

 Nature, lxix, 510, 533, 559. 



5. JSfew York State Museum. 2 2d Report of State Geologist, 

 1902. 186 pp., 29 pis. — In addition to the economic work con- 

 ducted under Dr. Merrill's direction, investigations on the crys- 

 talline and Pleistocene rocks were continued. 



New occurrences of anorthosite on the Langlake sheet are 

 reported and studied by Prof. Cushing. Prof. Woodworth con- 

 tinued his detailed study of the Hudson-Champlain depression 

 and mapped new shore lines marked by bars, embankments and 

 terraces. Pages 17-41 of the present report is a paper by Prof. 

 H. L. Fairchild on Glacial Waters from Oneida to Little Falls. 

 The history of the Mohawk Valley drainage is divided into three 

 stages: 1. Pre-Iroquois waters — lacustine, and fluviatile, held in 



