Maryland G-eo logical Survey 227 



Description. — Pinnules small and generally remote, the distal ones 

 short, all divided into three principal lobes which are variously dissected 

 and terminated with two or more short, stout teeth. Venation as usual 

 in this genus. 



This species is thus far confined to the Patuxent formation of Vir- 

 ginia, the specimens from Maryland so identified by Fontaine proving 

 to belong to AcrosticJiopteris longipennis, which is somewhat similar in 

 appearance but usually much more dense in habit. 



The remains are rare and fragmentary at all of the recorded localities 

 except Dutch Gap Canal, where they are not infrequent. They show no 

 traces of fructifications. This species is very closely related to Acrosti- 

 chopteris fimhriata Knowlton^ of the Kootanie formation of Montana, 

 and likewise to Acrostichopteris Ruffordi Seward ' of the English 

 Wealden. On the continent it is represented by the nearly allied and 

 strictly congeneric species Splienopteris tenellisecta Sap." from the Upper 

 Jurassic, and Splienopteris flabellisecta Sap.* from the Aptian of 

 Portugal. 



Occurrence. — Patuxent Formation. Dutch Gap, Fredericksburg, 

 Trents Eeach, Potomac Eun, Virginia (not Federal Hill, Md.). 



Collection. — U. S. ISTational Museum. 



Acrostichopteris pluripartita (Fontaine) Berry. 

 Plate XXIV, Fig. 6 



Baieropsis pluripartita Fontaine, 1890, Mon. U. S. Geol. Survey, vol. xv, 



1889, p. 208, pi. Ixxxix, fig. 4; pi. xc, figs. 2-5; pi. xci, figs. 1, 3, 4, 7; pi. 



xcii, figs. 1, 2, 6. 

 Baieropsis pluripartita minor Fontaine, 1890, Mon. U. S. Geol. Surv., vol. 



XV, 1889, p. 208, pi. xci, fig. 5; pi. xcii, fig. 3, 4. 

 Baieropsis longifolia Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, 



p. 210, pi. xci, fig. 6. 

 Baieropsis pluripartita 1 Fontaine, 1899, in Ward, 19tli Ann. Rept. U. S. 



Geol. Survey, pt. ii, p. 685, pi. clxviii, figs. 9-12. 



^Knowlton, Smith. Misc. Coll., vol. 1, 1907, p. 110, pi. xi, figs. 3, 3a. 

 =^ Seward, Wealden Fl., pt. i, 1894, p. 61, pi. vi, fig. 3. 

 ^ Saporta, Fl. Foss. Portugal, 1904, p. 25, pi. xiii, fig. 1. 

 * Saporta, IMd., p. 69, pi. xv, figs. 14, 15. 



