18 MARCHANTITES. 
Genus MARCHANTITES, Brongniart. 
[Tableau, p. 12.] 
Vegetative body of laminar form, with apparently dichotomous 
branches, and agreeing in habit with the recent thalloid Hepatice, 
as represented by the genus JJarchantia. 
Brongniart’s term Iarchantites is, in the present instance, pre- 
ferable to UMarchantia; the latter would suggest a fossil which 
might reasonably be regarded as a species of the recent genus ; 
the former has a wider meaning, and, if used in the broad sense 
indicated in the above definition, would refer rather to a type 
of vegetative body than to a special genus. 
1.—Marchantites Zeilleri, sp. nov. 
Type. Specimen in the British Museum. V. 23830. Discovered 
by Mr. Rufford. Pl. I. Fig. 3. 
“Frond” repeatedly divided by forked branching, apparently 
dichotomous. Average breadth about 3mm.; the branches have a 
distinct and fairly broad midrib, and on either side of the central 
axis are thin and filmy. 
I have named this Wealden species after Professor Zeiller, of 
Paris, who is one of the authors of the oldest known species of 
moss, and whose labours in palsobotany have done so much to 
establish the subject on a more scientific foundation. 
In habit and size this species very closely resembles Marchantva 
Chenopoda, Linn., from tropical America. No other genus, so far 
as resemblance in habit is concerned, agrees so nearly with the 
Wealden form as DMarchantia, but without trace of either male or 
female receptacle, or other aids to identification, no great stress 
should be laid on the comparison. ‘There is the same branching 
habit and distinct midrib in Leckenby’s species, Fucovdes erectus. 
In both the midrib is clearly shown by the much darker colour of 
the median portion of the thalloid impressions; the thinner lateral 
parts in the present species appear almost like brown stains on the 
matrix. A somewhat similar form, but without any striking 
resemblance, and, indeed, of much smaller size, is figured by Debey 
1 Quart. Journ. Geol. Soc. vol. xx. p. 74, pl. xi. fig 3. 
