* 
chairn, near Glasgow, a gentleman who, imbibing an carly taste 
for botany under the celebrated Dr CaNDOLLE at Geneva, 
has continued to pursue the study with great zeal; and durin 
an excursion which he lately made through the British settle. 
ments at Guaiana, collected a rich and abundant harvest of 
plants. These have been consigned to me, with a liberality 
that demands my warmest acknowledgments, together with nu- 
merous descriptions, made from living individuals, chiefly of 
those belonging to the tribe of Palms. Among his choice col- 
lection, are many specimens of the Fern now under considera- 
tion, in an excellent state of preservation. — 
€ nature of the capsules of this plant, and their situa- 
tion, require that a new Order in the Class Cryptogamia should 
be established for it, and I have named it after the only genus 
that is at present known to belong to the family. Perhaps its 
place should be near Marsileacee of Brown. 
The East Indian Pteris thalictroides of Swartz and 
WILLDENOw (Acrostichum, L.), has unquestionably many 
points in common with this plant, and it is equally of aquatic 
origin: but the fruetification is nowhere described with s 
cient accuracy to enable me to speak satisfactorily upon the 
point of their affinity, and I have not had the opportunity 
" OF seeing specimens. I cannot, however, help expressing it as 
my opinion, that P. thalictroides * will rank in the same ge- 
nus with the present subject of our consideration. As a spe- 
cles, it may be distinguished by its having sterile fronds, diffe- 
rent from the fertile ones: whereas in all the specimens of 
Parkeria pteridoides, the fronds are alike. 
nother plant, allied to this, is the Pleris cornuta of Pa- 
LISOT DE Brauvois’ Flore d’Oware et de Bénin, P. 62. t. 37. 
That author, however, both describes and figures the capsules 
as furnished with an annulus, and having seeds quite different 
from those of Parkeria. This grows in salt-water pools on 
the coast of Africa. . 
* . ARKER finds the present fern in fresh-water ditches, 
in the district of Essequibo. 
ne rae erate eae 
Fig. 1. Portion of the frond. Figs. 2. & 4. Under side of a portion. Fig. 3. 
Back view of ditto. Fig. 5. Under side, with the involucre laid open, 
to shew the situation of the capsules. Fig. 6. Capsules. Fig. 7. Cap- 
sule torn open. Fig, 8. Seeds.—All more o less magnified. 
* This is mentioned by Mr Brown, Prodr. Fl. Nov. Holl. p- 154. as ee 
new genus; and, since the above was printed, I find that, in Franklin’s Journal, ait 
under the article Cryptogramma, Mr Brown has called it Teleoxoma, and assigns to 
** Capsule Sessiles, annulo completo latissimo.” Hence, however closely these two gene ily 
Cryptogramma and Teleozoma, may be allied to our plant in habit, they are essentially 
different in the structure of the fructification. 
