276 Systematic Paleontology 



OnycMopsis MantelU Seward, 1900, Fl. Wealdienne de Bernissart, mem. 



Musee Roy. d'hist. nat. de Belgique, Annee 1900, p. 15, pi. i, figs. 17-19; 



pi. li, figs. 20, 21. 

 OnycMopsis MantelU Seward, 1903, Ann. S. Afr. Mus., vol. iv, p. 5, pi. i; 



pi. V, fig. 1. 

 Thyrsopteris insignis Fontaine, 1906, in Ward, Men. U. S. Geol. Surv., vol. 



xlviii, 1905, p. 521. 

 Thyrsopteris angustifolia Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., 



vol. xlviii, 1905, p. 516. 

 Thyrsopteris rarinervis Fontaine, 1906, in Ward, Mongr. U. S. Geol. Survey, 



vol. xlviii, pp. 225, 484, 491, 514, 517, 518, 519, 521, 528, 548, 558, pi. 



Ixv, figs. 2-4; pL cxiii, figs. 2, 3. 

 OnycMopsis psilotoides Ward, 1906, in Fontaine, in Ward, Mon. U. S. Geol. 



Surv., vol. xlviii, 1905, p. 155 (name only). 

 OnycMopsis psilotoides Fontaine, 1906, IMd., pp. 506, 518, 528, pi. cxi, fig. 



4; pi. cxiii, fig. 1. 

 OnycMopsis MantelU Richter, 1906, Beitr. z. Fl. der unteren Kreide Qued- 



linburgs, Teil. 1, p. 6. 

 OnycMopsis psilotoides Knowlton, 1908, in Diller, Bull. Geol. Soc. Am., 



vol. xix, 1908, p. 380. 

 OnycMopsis psilotoides Berry, 1911, Proc. U. S. Natl. Mus., vol. xli, p. 330. 



Description. — " S. foliis bipinnatifidis^ pinnis approximatis virgatis 

 fastigiatis, pinnulis obliquis, omnibus integris iminerviis, angustis, cune- 

 atis, apice oblique truncatis et subemarginatis ; parte exteriori longius 

 producta?' — Brongniart;, 1828. 



" Frond tripinnate, ovate lanceolate, rachis winged and prominent ; 

 pinnse lanceolate, alternate, approximate, given off from the main rachis 

 at an acute angle. Pinnules alternate, narrow, lanceolate acuminate, 

 uninerved, of nervation type Coeopteridis (Luerssen, in Eabenhorst's 

 Krypt. PL, vol. iii, p. 11) ; the larger ones serrate and gradually passing 

 into pinnge with narrow ultimate segment. Pructification in the form 

 of sessile or shortly stalked linear ovate segments with rugose surfaces, 

 and terminating usually in a very short awn-like apical prolongation." — 

 Seward, 1894. 



The foregoing are respectively the first and last diagnoses of this 

 species and will suffice for the Maryland forms, with the exception tliat 

 fertile specimens are altogether unknown thus far in this region. 



This species is not nearly so common in the Potomac as is Onychiopsis 

 Gcepperti, although it appears to have a Avider range and to be more 

 common abroad. It occurs at all horizons- in the Potomac, however, a 

 vertical range which is paralleled by its range from the Valanginian 



