134 MICRODICTYON 



V. 2381. A triangular apical portion of a pointed leaflet. The 

 apex seems to vary considerably in form ; it may be either pointed 

 or distinctly obtuse. Ecclesbourae. Ruford Coll. 



? V. 2735. Here are two small leaflets which should possibly 

 be included in this species; on the same specimen is a piece 

 of ?stem structure, with which one of the leaflets is in close 

 contiguity, suggesting a pinnule attached to a rachis. There 

 is, however, no clear evidence of such attachment, and I prefer 

 to regard the juxtaposition as one of the many misleading accidents 

 of fossilization. Midrib more distinct than in most specimens of 

 S. Mantelli. Ecclesbourae. Ru/ord Coll. 



Genus MICRODICTYON, Saporta. 

 [Pal. Fran9. 1873, Plantes Jurassiques, vol. i. p. 306.] 



This genus was founded by Saporta for the inclusion of certain 

 Jurassic ferns which did not conform in all points to the existing 

 genera PTilebopteris and Thaumatopteris, with which they closely 

 corresponded in general habit. The chief characteristics of the 

 genus are the reticulately disposed lateral veins between the 

 stouter lateral branches, which are given off at right angles to the 

 midrib, also the occurrence of a single row of son on each side of 

 the midrib. From Phlelopteris Saporta's genus is distinguished by 

 the network of fine veins in the large areolse between the stronger 

 lateral veins, and from Thaumatopteris by the more regularly- 

 placed and fewer sori. The genus is referred to the tribe 

 Polypodies. 



"Frons pinnata vel saltern frondis segmenta pinnatipartita, 

 pinnis linearibus elongatis ; nervi e costa primaria pinnularum orti 

 sub angulo aperto emissi, dein arcuatim conjuncti, arcolas secus 

 nervum medium seriatas efformantes, intus reticulum sorosque 

 rotundos puncto medio solitarie affixes includentes, extus venulas 

 pluries furcato-divisas inter seque varie anastomosatas marginem 

 usque integerrimum emittentes." l 



1 Saporta, Pal. Fraiu;. vol. i. p. 306. 



