Maryland Geological Survey 281 



It is widely distributed throughout the Potomac Group, but not com- 

 mon at an}^ outcrop. Outside this area it has been reported from the 

 Lakota formation of the Black Hills. Practically identical remains from 

 the Lower Cretaceous of Portugal are described by Saporta as various 

 species of Sphenopteris. 



Occurrence. — Pattjxent Formation. Fredericksburg, Dutch Gap, 

 Potomac Eun, Virginia; A^ew Eeservoir, Ivy City, District of Columbia; 

 Springfield, Maryland. Arundel Formation. Langdon (frequent). 

 District of Columbia. Patapsco Formation. Chinkapin Hollow, A^ir- 

 ginia; Ft. Foote, near Glymont, Vinegar Hill (?), Federal Hill (Balti- 

 more), Maryland. 



Collections. — U. S. JSTational Museum, Maryland Academy of Science, 

 Goucher College. 



Onychiopsis Gcepperti (Schenk) Berry 

 Plate XXXIV, Figs. 3, 4 



Sphenopteris Goepperti Schenk, 1871 (pars), Palseontographica, Band xix, 



1871, p. 7 (209), pi. iv, fig. 2 (non figs. 3-5 or pi. ix, fig. 2). 

 Thyrsopteris elongata Geyler, 1877, Palaeontographica, Band xxiv, p. 221. 

 Thyrsopteris elongata Schenk, 1883, in Richthofen's China, Band iv, p. 



263, pi. liv, fig. 1. 

 Dicksonia elongata Yokoyama, 1886, Bull. Geol. Soc, Japan, vol. i. No. 1, 



p. 5. 

 Onychiopsis elongata Yokoyama, 1890, Jour. Coll. Sci., Japan, vol. iii, p. 27, 



pi. ii, figs. 1-3; pi. iii, fig. 6d; pi. xii, figs. 9, 10. 

 Onychiopsis elongata Nathorst, 1890, Denks, k. Akad. Wiss., Wien, Band 



Ivii, pp. 44, 48, 50, 51, 52, 53, 54, pi. v, fig. 3; pi. vi, fig. 5. 

 Thyrsopteris alata Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 



124, pi. xxxvi, fig. 3. 

 Thyrsopteris Meekiana angustiloba Fontaine, 1890, Mon. U. S. Geol. Surv., 



vol. XV, 1889, p. 126, pi. xxxviii, figs. 5-7, 9; pi. xliii, fig. 8; pi. xliv, fig. 



3; pi. xlvii, fig. 4; pi. xlviii, fig. 1; pi. liv, figs. 2, 11; pi. Iv, fig. 1; pi. 



Ivi, figs. 1, 3. 

 Thyrsopteris angustiloha Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 



1889, p. 134, pi. xlviii, figs, 3-5; pi. Iv, fig. 3. 

 Thyrsopteris densifolia Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 



1889, p. 129, pi. xxxix, fig. 3; pi. xl, figs. 2-5; pi. li, fig. 5. 

 Thyrsopteris deciirrens Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 



1889, p. 130, pi. xliii, fig. 7; pi. xlvi, figs. 2, 4; pi. xlix, figs. 5-7. 

 Thyrsopteris virginica Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, 



p. 120, pi. xxiv, fig. 1. 



