66 BIBLIOGRAPHY OF NORTH AMERICAN GEOLOGY, [bull. 203. 
572 Obalski (J.). Notes on the magnetic iron sand of the north shore 
of the St. Lawrence [Canada]. 
Can. Mg. Rev., vol. 20, pp. 34-37, 1 fig., 1901. 
Can. Mg. Inst. Jour., vol. 4, pp. 91-98, 1 fig., 1901. 
Gives chemical analyses of the sand and describes its distribution. 
573 Ordonez (Ezequiel). Las rhyolitas de Mexico. I. 
Mexico Inst. Geol., Bull. No. 14, 75 pp., 5 pis., 1900. 
Bull. No. 15, 76 pp., pis. 1-11, 1901. 
Describes the macroscopic and microscopic characters of the rhyolites 
and their distribution. 
574 La industria minera en Mexico. 
Ciencia y Arte, Mexico, 19 pp., 1901. (Not seen.) 
575 The mining district of Pachuca, Mexico. 
Eng. and Mg. Jour., vol. 72, pp. 719-721, 1901. 
Contains notes on the geology and mineralization of the region. 
576 Ortmann (Arnold E.). The theories of the origin of the Antarctic 
faunas and floras. 
Am. Nat., vol. 35, pp. 139-142, 1901. 
Reviews the literature on the subject. 
577 Orton (Edward). Petroleum and natural gas in New York. 
N. Y. State Mus., 53d Ann. Kept., vol. 1, pp. 391-526, 3 maps, 1901. 
See Bull. U. S. Geol. Surv., No. 188, Orton No. 4172. 
578 Osborn (Henry Fairfield). The recent progress of vertebrate 
paleontology in America. 
Science, new ser., vol. 13, pp. 45-49, 1901. 
Abstract of lecture delivered at Trinity College, Hartford, Conn. 
579 Recent zoo-paleontology. 
Science, new ser., vol. 14, pp. 330-331, 1901. 
Contains notes on papers relating to the John Day beds and to the 
Kansas chalk. 
580- - [Review of "Diplodocus Marsh. Its osteology, taxonomy, 
and probable habits, with the restoration of the skeleton" 
by J. B. Hatcher.] 
Science, new ser., vol. 14, pp. 531-532, 1901. 
581 Recent zoo-paleontology. 
Science, new ser., vol. 14, pp. 699-700, 1901. 
Reviews Wortman's work on the Carnivora and Gidley's work on 
Pleistocene horses. 
582 Des methodes precises mises actuellement en ceuvere dans 
Fetude des vertebres f ossiles des Etats-Unis d'Amerique. 
Int. Cong. Geol., Compte Rendu, viii session, pp. 353-356, pis. i-ii, 
1901. 
