30 M. YOKOYAMA. 



veins mann, equal, divergent, repeatedlg ddcliotomons. 



This fern seems to have been pretty slender in its general ap- 

 pearance. Along a rhachis, which is by no means strong, are arrang- 

 ed alternate or opposite, elongated pinnae more or less directed forward, 

 but often bent apparently by the weight of ovately or obovately 

 lanceolate, thick, entire pinnules, which are tolerably acutely di- 

 rected forward. Veins are pretty distinct, and radiate towards the 

 apex and margin of the pinnules, two to five times forking on their 

 way (fig. 7a). 



This species is closely related to the preceding in the form of the 

 pinnules which, however, are not in this case lobed. 



Very scarce. Lo.c. — Sh.ima.mnra. 



11. Adiantites laneeus m. 

 PI. XIV, fig. 3, 8a. 



Pinnules alternate, acutely directed forward, lanceolate, acute at apex, 

 constricted at base, entire: reins numerous, equal, divergent, repcatedl;/ 

 dichotomaus. 



Along a slender rhachis, are arranged lanceolate pinnules winch 

 are tolerably acutely directed forward. At the base they are sensibly 

 narrowed and apparently provided with a short petiole. They appear 

 to have been thin in texture, with numerous distinct veins diverging 

 towards the apex and margin, and repeatedly dichotomizing on their 

 way (fig. 3a), reminding as of the venation of many of the recent 

 Adiantums. None of the pinnules in our specimen are perfect ; but in 

 two of them, in which the apex and base are preserved, the length 

 measures 50—42 mm. and the breadth 6t — 7 mm. 



I know none among the Mesozoic plants which can aptly be com- 

 pared to this species. The preceding species, to which it bears some 

 r semblance in form of the pinnules and the mode of venation, has 



