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. Ecclesbourne. Rufford 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. Ecclesbourne. Rufford Coll. 
Genus MICRODICTYON, Saporta. 
[Pal. Frang. 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 Phlebopteris 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 sori on each side of 
the midrib. From Phlebopteris Saporta’s genus is distinguished by 
the network of fine veins in the large areole between the stronger 
lateral veins, and from Zhaumatopteris by the more regularly- 
placed and fewer sori. The genus is referred to the tribe 
Polypodiee. 
‘‘Frons pinnata vel saltem 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 affixos includentes, extus venulas 
pluries furcato-divisas inter seque varie anastomosatas marginem 
usque integerrimum emittentes.”’ ! 
1 Saporta, Pal. Franc. vol. i. p. 306. 
