Makyland Geological Survey ^6? 



AsPLENioPTERis ADiANTii'OLiA Fontaine 



Aspleniopteris adiantifolia Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 

 1889, p. 118, pi. xvi, fig. 6. 



Description. — " Sterile frond not seen ; fertile frond bipinnate or bi- 

 pinnatifid ; pinnules or lobes reduced to leathery thick pedicels or sup- 

 ports, which bear on their anterior or upper margin narrowly elliptical 

 or oblong sori ; sori proportionally very large." — Fontaine, 1890. 



This species was based upon the single specimen figured by Fontaine, 

 which is so poorly preserved that it has not been refigured. Jt was 

 found in association with the preceding species, and it seems very prob- 

 able that it represents merely a poorly preserved and perhaps abortive or 

 pathological fertile pinna of the former. 



Occurrence. — Patuxent Formation. Fredericksburg, Virginia. 



Collection. — U. S. National Museum. 



Genus ONYCHIOPSiS Yokoyama 

 [Jour. Coll. Sci., Japan, vol. iii, 1890, p. 26] 



Yokoyama characterized this genus as follows : " Fertile segments 

 different from the sterile. Sori terminal, linear, on each side of the 

 midrib, parallel with the margin, involucrate; the involucrum of each 

 side confluent over the midrib." It was based on a Japanese Jurassic 

 species originally described by Geyler as Thyrsopteris elongata and 

 founded upon sterile pinnules. The discovery of fertile pinnules by 

 Yokoyama led to the erection of the present genus, which is very close 

 to the modern genus OnycJiium Kaulfuss, which is made a subgenus of 

 Cryptogramme E. Brown by Diels in Engler and Prantl's Katiirlichen 

 Pflanzenfamilien (1899), although there seems to be but slight warrant 

 for Diel's treatment. 



Seward, in working over the abundant Wealden material in the British 

 Museum, found that the widespread species which usually went by the 

 name of Sphenopteris Mantelli Brongniart was congeneric with Yoko- 

 yama's species mentioned above, and he therefore redescribed Bron- 

 gniart's species as Onychiopsis Mantelli, redefining the genus in the fol- 

 lowing terms ^ : " Frond tripinnate, main rachis slender, may be vsdnged, 



^ Seward. Wealden Fl., pt. i, 1894, p. 40. 



