350 Wm. A. Norton on the Variations 



Culm 3-8 inches high, erect, triquetrous, at length nearly 

 prostrate with sheathing leafy bracts shorter than the culm, and 

 with broad radical leaves distinctly three-nerved : staminate spike 

 clubform, short, short-pedunculate, with oblong acute scales; pis- 

 tillate spikes two, or three often, few and loose-flowered, exsertly 

 pedunculate a little, and a little shorter than the leaf of the bract ; 

 stigmas three ; fruit ovate triquetrous, smooth and nerved, acute 

 at apex and turned slightly one side ; pistillate scale ovate, acute or 

 cuspidate, white on edge, shorter than the fruit; leaves pale green. 



Open woods over the country, but has been placed under C. 

 plantaginea and C. anceps. By Muh. both these were blended 

 together, though far different. By Schk. they were only half 

 distinguished, as he placed the wide leafed C. anceps under C 

 plantaginea, while he gives'a correct figure of the latter on Tab. 

 U, fig. 70, and of the former (C anceps) on Tab. Kkkk, fig. 

 195, and of the narrow leafed C anceps on Tab. Fff, fig. 128, 

 as they have been for years understood. These two need to be 

 separated ; and T propose to call the wide leafed C. anceps, C- 

 patulifolia, leaving to the narrow leafed its proper name as descri- 

 bed by Schk., and not confounding it with C. conoidea, Muh., 

 the C. bland a, Dewey. 



C. platyphylla was properly separated by Mr. Carey and pub- 

 lished in Prof. Gray's Botany of the Northern States, and placed 

 in the section with C. plantaginea, Lam., and C. Careyana, Dew. 



Note. — C. alopecoidea, Tuckerman, var. sparsi-spicata, Dew., 

 has scattered spikelets, forming a compound spike three inches 

 long, and not an aggregated head of spikelets. 



In Washington, Mich. — Dr. Cooley. 



C. intermedia, Good., is found by Dr. Geo. Vasey in Ring- 

 wood, 111. 



C. fcenea, Muh., has been found abundantly by Mr. Olney iu 

 Cumberland, R. I. 



Art. XXV. — On the Diurnal Variations in the Declination of 

 the Magnetic Needle, and in the Intensities of the Horizontal 

 and Vertical Magnetic Forces ; by William A. Norton, Pro- 

 Mathematics and Natural Philosophy in Delaware 



(Continued from p. 226.) 



College. 



We 



secondary nocturnal variations of the horizontal magnetic inten- 

 sity of a place, correspond, in respect to time and direction, with 

 the deviations in the nocturnal loss of temperature from uniform- 

 ity, and that the cause of these deviations is therefore, in all prob- 

 ability, either identical with or closely related to the cause of the 





