weeks.] PALEONTOLOGY, PETROLOGY, AND MINERALOGY, 1895. 65 
387 RaufF ( Hermann ). Ueber Porocystis prnuiformis Cragin ( = ? 
Arancarites wardi Hill) aus der nnteren Kreide in Texas. 
Neues Jabr. fiir Min. ; etc., 1895, Band i, pp. 1-15. 
Describes tbe cbaracters of tbe fossil, and reviews tbe descriptions of 
Messrs. Hill and Cragin. 
388 Raymond (R. W.). [The torsional theory of joints.] 
Am. Inst. Mg. Engrs., Trans., vol. xxiv, pp. 864-865. 
In discussion of paper by G. F. Becker on tbe same subject. 
389 [Pyrrhotite deposits at Anthonys Nose, New York]. 
Am. Inst. Mg. Engrs., Trans., vol. xxiv, pp. 886-888. 
In discussion of paper by J. F. Kemp on " Tbe nickel mine at Lancas- 
ter Gap, Pennsylvania, and tbe pyrrbotite deposits at Antbonys Nose 
on tbe Hudson. 7 ' 
• 
390 [The classification of ore deposits.] 
Am. Inst. Mg. Engrs., Trans., vol. xxiv, pp. 956-957. 
Remarks on a classification of ore deposits presented in T. A. Rickard's 
discussion of a paper on tbe " Genesis of ore deposits/' by F. Posepny. 
391 [The genesis of ore deposits.] 
Am. Inst. Mg. Engrs., Trans., vol. xxiv, pp. 980-995. 
In discussion of paper by F. Posepny on tbe same subject. 
392 R[aymond (R. W.).] The superficial alteration of ore deposits. 
Eng. and Mg. Jour., vol. lix, p. 328. 
Reviews paper by R. A. F. Penrose, jr., on tbe same subject. 
393 Reid (Harry Fielding). The variations of glaciers. 
Jour, of Geol., vol. iii, pp. 269-288. 
Abstract : Geol. Soc. Am., Bull., vol. vi, pp. 461-462 (£ p). 
Discusses tbe causes of variations in glaciers, and describes the obser- 
vations tbat should be made in studying glacial phenomena. 
394 Rhoads (Samuel N.). Distribution of the American bison in 
Pennsylvania, with remarks on a new fossil species. 
Phila. Acad. Nat. Sci., Proc, 1895, pp. 244-248. 
Remarks on the former occurrence of the American bison in Pennsyl- 
vania, and describes a new species, Bison appalachicolus. 
395 Rickard (T. A.). [The genesis of ore deposits.] 
Am. Inst. Mg. Engrs., Trans., vol. xxiv, pp. 942-956. 
In discussion of paper by F. Posepny on the same subject, presents the 
author's classification of ore bodies, and discusses phenomena observed 
in mines in Colorado and Arizona. 
39G Porphyry. 
Eng. and Mg. Jour., vol. lix, p. 578. 
Discusses the characters of porphyries and their occurrence in different 
mining regions. 
397 Variations in the milling of gold ores, xii. The Black Hills, 
South Dakota. 
Eng. and Mg. Jour., vol. lx, pp. 221-223 and 247-251. 
Describes briefly some of the ore bodies of tbe Black Hills. 
Bull. 140 5 
