313 Systematic Paleontology 



Equisetum Lyelli Schimper, 1869, Traite Pal. V^get, tome i, p. 265; tome, 



iii, 1874, p. 453. 

 Equisetum Lyelli Schenk, 1871, Palaeont., Band xix, 1871, p. 5 (207), pL i, 



figs. 10-13. 

 Equisetites Lyelli Renault, 1882, Cours bot. foss., tome ii, p. 150. 

 . Equisetum Lyelli Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 



65, pi. i, fig. 7; pi. ii, figs. 4, 5. 

 Rhizome of Equisetum sp. ? Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 



1889, p. 65, pi. ii, fig. 8. 

 Equisetum Lyelli Dawson, 1892, Trans. Roy. Soc. Can., vol. x, sec. iv, p. 83, 



fig. 1. 

 Equisetites Lyelli Seward, 1894, Wealden Fl., pt. i, p. 24, pi. i, fig. 4. 

 Equisetum Lyelli Fontaine, 1898, in Weed and Pirsson, 18tli Ann. Rept. 



U. S. Geol. Surv., pt. iii, p. 481. 

 Equisetum Lyelli Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. 



xlviii, 1905, pp. 301, 417, 514, pi. Ixxii, figs. 12-14. 

 Equisetites Lyelli Neumann, 1907, Neues Jahrb. Beilage, Band xxiv, p. 77, 



pi. i, fig. 2. 



Description. — " Caulis epigasus cylindrieus articulatus ramosus, inter- 

 nodia 2 centim. longa, 10-13 millim. in diametro, rami 5 millim. in 

 diametro, folia sterilia vaginata, vaginas 1 centim. longse, dentes lineares 

 acnminati persistentes." — Schenk, 1871. 



A somewliat larger species than the preceding, with stems .6 cm. to 

 1.5 cm. in diameter, Internodes 2 cm. to 2.5 cm. in length. Single 

 branches are of frequent occurrence at the nodes in the foreign material, 

 and it is probable that the smaller Potomac specimens represent detached 

 branches. The sheaths are about a centimetre in length, with numerous 

 linear acuminate teeth. Internodes finely striated. 



The American remains are usually fragments of stems, and like those 

 of the preceding species are generally very poorly preserved. Described 

 originally from the Wealden of Pounceford, England, this species has 

 been recognized at Fredericksburg, Dutch Gap, and Chinkapin Hol- 

 low ( ?) by Fontaine. Dawson found it in the Kootanie of Canada and 

 Fontaine reports it from the same formation at Geyser, Montana. It 

 has also been recorded recently from the Neocomian of Peru.'' 



Occurrence. — Patuxent Formation. Springfield (?), Maryland; 

 Fredericksburg, Chinkapin Hollow ( ?), Dutch Gap, Virginia. 



Collection. — ^U. S. National Museum. 



^ Neumann, loc. cit. 



