180 BOTANICAL GAZETTE [FEBRUARY 
authors explain this feature by compression during fossilization. 
In this case also the mechanical. orientation of the Ammnularia 
whorls in the thousands of specimens which have been collected 
is difficult if not impossible of adequate explanation if the theory 
that the leaves in life radiated at right angles to the axis be adopted. 
The present specimen comes from the immediate vicinity of the 
old Carbon Hill mine, about one mile south of Gayton on Tuckahoe 
Creek, near the western border of Henrico County, Virginia, from 
beds of undoubted Rhaetic age, and the type is deposited in the 
U.S. National Museum, duplicate and less perfect material being 
retained in the collections of the Johns Hopkins University. 
Jouns Hopxins UNIVERSITY 
BaLtmMoreE, Mp. 
- LITERATURE CITED 
1. Emmons, E., Geol. rept. of the midland counties of North Carolina. 
Raleigh. 1856. 
. Fontatne, W. M., Contribution to the knowledge of the older mesozoic 
flora of Virginia. Monograph U.S. Geol. Surv. 6:1883. 
3. Harte, T. G., Zur Kenntnis der mesozoischen Equisetales Schwedens. 
Kgl. Svenska Vetens.-Akad. Handl. 43:pp. 56. pls. 9. 190 
4. Krasser, F., Zur Kenntnis der fossilen Flora ae ee Schichten. 
Jahrb. Geol. Reichs. 59:10I-126. 1900. 
5. LicNrER, O., Calamitomyelon Morierei, gen. et sp. nov. Bull. Soc. Linn. 
Normandie VI. 2:116-128. pls. 1-3. 1908 
6. SHALER, N. S., and Woopworts, J. B., Geology of the Richmond Basin, 
Virginia. roth Ann. Rept. U.S. Geol. Surv. IT. 1899: 385-520. 
Stur, D., Die Lunzer (Lettenkohlen) Flora in den “Older mesozoic beds 
of the coal-field of eastern Virginia.” Verh. Geol. Reichs. Wien. 1888: no. 
IO. 203-217. 
arp, L. F., with the collaboration of FonrarnE, W. M., WANNER, 
ATREvS, and KNow ton, F. H., Status of the mesozoic floras of the United 
States. First paper: The older mesozoic. 20th Ann. Rept. U.S. Geol. 
te . I. 1900:211-748. pls. 21-17 
: TE, Davin, Fossil flora of the cual measures of Brazil. III. Rept. 
Brazilign Coal Commission 1908: 337-617. 
. Wits, L. J., The eae tot6 lower Keuper rocks of Worcestershire. 
Proc. Geol. Ass. 21:271-287. 1 
mus, L. J., Notes on the Hot stregge Schimper and Mougeot. 
Proc. Cambridge Phil. Soc. 15:406-410. 19 
12. ZEILLER, RENE, Les progrés de la ieee de l’ére des gymno- 
spermes. Progressus Rei Botanicae 2:171-226. 1907. 
13. ZEILLER, R., Fl. foss. des gites de charbon du Tonkin. Paris. 1903. 
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