2G0 JOURNAL OF THE WASHINGTON ACADEMY OF SCIENCES VOL. 11, NO. 11 



GEOLOGY. — Geology of Alamosa Creek valley, Socorro County, New Mexico, 

 with special reference to the occurrence of oil and gas. Dean E. Win- 

 chester. U. S. Geol. Survey Bull. 716-A. Pp. 15 (1-15), pis. 5. 1920. 

 This report is based on a field study of the coal resources of the region. 

 Structure is therefore discussed only in a general way and not represented by 

 contours. The geography of the valley lying between the Continental Divide 

 on the west, smaller Tertiary mountain ranges to the south, and the Sierra 

 Ladron on the east, is briefly described. About 8,000 feet of sedimentary 

 rocks from Carboniferous to Recent are exposed. Carboniferous and Triassic 

 represented by red beds are unconformably overlain by Cretaceous consisting 

 of the Dakota sandstone at the base, with a series of shales, sandstones and 

 coal beds overlying it. This upper series is divided into the Miguel formation 

 roughly equivalent to the Mancos shale but more sandy; and the overlying 

 non-marine Chamiso formation containing a Mesaverde flora. Unconform- 

 ably on the Cretaceous lies the Tertiary Datil formation, largely volcanic 

 with associated sandstones and conglomerates. Quaternary terrace gravels 

 overlie all of these, and all formations except the younger terrace gravels are 

 capped by lava flows. Structurally the area is the southeastern part of the 

 San Juan Basin from the rest of which it is largely separated by the northwest 

 trending Zuni Mountain uplift. The prevailing dip at low angles to the west 

 is interrupted by many faults and minor folds and cut by dikes, most of which 

 trend roughly parallel to the Zuni Mountains. As possible source of oil three 

 larger anticlines are described, the largest 13 miles long. The presence of 

 abundant carbonaceous shales, of coal with about 55 per cent fixed carbon, 

 and of several massive persistent sandstones in the Miguel formation, which 

 can be tested by holes less than 2,000 feet deep, afi"ord favorable indications 

 for the presence of accumulations of oil. The formations older than the 

 Cretaceous may also contain oil accumulations. M. I. Goldman 



BOTANY. — Another conidial Sclerospora of Philippine maize. William H. 

 Weston, Jr. [ourn. Agric. Research 20: 669-684. Pis. 4, figs. 1. 

 1921. 



Another conidial Sclerospora is involved in the destructive maize downy 

 mildew of the Philippines in addition to Sclerospora philippinensis, the 

 casual fungus previously described. This second species, found in the 

 Islands of Cebu' Bohol and Leyte, occuring commonly on maize, rarely on 

 the wild grass, Saccha-um spontaneum, and once on sugar cane, differs from 

 5. philippinensis in that the conidiophores are generally longer and more 

 slender, the basal cells are of much greater length in relation to the main 

 axis, while the conidia especially are longer and less broad; and is described 

 as new under the name of Sclerospora spontanea. These specific morpholog- 

 ical differences remain constant even through several generations on a 

 range of hosts, including maize, teosinte (Euchlaena spp.), Miscanthus japoni- 

 ciis, and Saccharum spontanem. The size and shape of the conidia, the 

 most valuable criteria of interspecific distinction, are given in detail, meas- 

 urements of 700 conidia of each being presented in tables and graphs, and 

 the more significant biometric constants being compared. Although morpho- 

 logically distinct, the two species are alike physiologically in their effect 

 on and in their virulence to the same host species. The probable relation- 

 ship of the two fungi to the other conidial Sclerosporas of the Orient and to 

 the oogonial stages of the Philippines is discussed. The occurrence of 



