Analytical Abstracts of Current 

 Literature. 



A New Tc^iiiopteroid Fern and its Allies. By David White. (Bul- 

 letin Geological Society of America, 4 pp., 1 19-122, pi. I.). 

 Mr. White has described, under the name of Tceniopteris missouriensis, 

 a new and well characterized fern from the Lower Coal-measures in the 

 vicinity of Clinton, Henry County, Missouri. Botanically, it is of particular 

 interest in that it combines the so-called taeniopteroid and alethopteroid types 

 of structure, while geologically it is of much value in supplying a readily 

 identified stratigr^phic mark in a part of the Carboniferous not especially 

 rich in fossil plants. After thoroughly describing it and considering its spe- 

 cific and generic resemblances, the author discusses at length its suggested 

 genetic relations and represents in a graphic manner a scheme of its prob- 

 able ancestors and line of descent. F. H. K. 



Rainfall Types of the United States. Annual Report by Vice-Presi- 

 dent General A. W. Greely. (The National Geographic 

 Magazine. Vol. V., April 29, 1S93, pp. 45-58 pi. 20). 



The paper confines itself to the characteristic distribution of precipitation 

 throughout the year and gives the rainfall types of the country. 



(a) The best defined type of rainfall within the United States is that 

 which dominates the Pacific coast region as far east as western Utah. The 

 characteristic features are a very heavy precipitation during midwinter, and 

 an almost total absence of rain during the late summer, (b) The charac- 

 teristics of the Mexican type, dominating Mexico, New Mexico and western 

 Texas, are a very heavy precipitation after the summer [solstice and a very 

 dry period after the vernal equinox. August is the month of greatest rain- 

 fall, while February, March and April are almost free from precipitation, 

 (c) The Missouri type covers the greatest area, dominating the water- 

 sheds of the Arkansas, Missouri and upper Mississippi rivers, and of lakes 

 Ontario and Michigan. It is marked by a very light winter precipitation, 

 followed in late spring and early summer by the major portion of the 

 yearly rain, the period- when it is most beneficial to the growing grain. 



Abstracts in this number are prepared |by F. H. Knowlton, Henry B. Kummel, 

 J. A. Bownocker. 



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