1386 MICRODICTYON 
possession bears the date 1870, the title page being dated 1871; 
according to the reprint, therefore, we ought to regard Traut- 
schold’s species as having priority over Schenk’s. Considering 
the better material and much more complete diagnosis given by 
Schenk, I propose to retain his name, in spite of the possible 
priority of the Russian species. 
Schenk, in his first notice of Microdictyon Dunkeri, compares it 
to Laccopteris elegans, Presl, of Rheetic age; in his second paper it 
is transferred to Saporta’s genus, and much new information is 
added with regard to the fructification. He considers that the 
fragments are most probably part of a palmately-divided leaf, 
and agrees with Saporta that Microdictyon comes nearest to certain 
species of the recent genus Polypodium. 
The smaller form from Portugal, named by Heer Laccopteris 
pulchella,* is admitted by the author of the species to bear a close 
resemblance to LZ. Dunkeri, but it is separated on account of the 
difference in size of the ultimate segments, and for some other 
reasons, the force of which is not very clear. It is not improbable 
that we might be right in including Heer’s species in the list 
of synonyms, but, considering the imperfections of the type speci- 
men of L. pulchella, it is better, perhaps, to retain this additional 
specific name. 
From the Cretaceous plant beds of Bohemia Velenovsky describes 
some larger specimens than have been accessible to earlier writers ; 
they resemble in all points the smaller pieces figured by Schenk. 
The affinity of the plant is discussed, and the two genera Gleichenia 
and Cyathea* are chosen as the most likely living ferns with which 
the fossil form must be compared; this comparison is founded on 
the character of the sori, but Velenovsky’s specimens showed no 
trace of the individual sporangia. He does not mention Schenk’s 
figures and descriptions of well-preserved fertile segments, although 
the volume in which the Bohemian ferns are described bears the date 
1888, twelve years later than the publication of Schenk’s memoir. 
In Andrae’s account‘ of the plants from the ‘Liassic’’ beds 
of Steierdorf there are several figures of Andriania baruthina, 
Fr. Braun, which are exactly similar in habit to Iverodictyon 
1 Paleontographica, vol. xxiii. p. 162. 
* Sece. Trab. Geol. Portugal, 1881, p. 16, pl. xv. fig. 7. 
3 Abh. k. bohm. Ges. Wiss. 1888, p. 13. 
* Abh. k.-k. geol. Reichs. vol. ii. Abth. iii, No. 4, p. 36, pl. vii. figs. 1-3. 
