306 
things, and quite conclusively shows that they are dicecious pro- 
thalli of Ferns (“An ad Hymenophylleas pertinet?”), and consid- 
ers them perennial. However, he winds up his remarks by saying 
that he leaves the whole matter in the greatest doubt (!) The form 
which Swartz referred to Ricca was referred to the Lichenes by 
Acharias, and to the 4/g@ by Aghardh.—There can be but little 
doubt that the plant described in this Journal (vol. VI, p. 188) by 
Mr. Wolle, as an Alga, under the name of Poterophora Donneltii, 
nov. gen. et sp.,is also the prothallus of some dioecious fern or 
filicoid. In structure it too is much like a Ziverwort; e. g. Jung. 
confervifolia. Gott. [Almost from the beginning of my acquaint- 
ance with the Liverworts, I have been possessed with the fancy that 
the Ferns are but a higher development of them; also that they 
(the Liverworts) are but a higher development of the simpler 4/ge. | 
§ 300. New or Little-known Ferns of the United States. No. 6. 
16, Adiantum tenerum, Swartz.—Distinguished from Ad. Capil- 
lus-Veneris by the broadly deltoid-ovate outline of the commonly 
much larger 3—4-pinnate fronds, and especially by having the ulti- 
mate pinnules articulated to their petioles, so that after maturity they 
all fall off, leaving the rachis and all its branches and branchlets 
bare of foliage. The ultimate pinnules vary from rhomboid to 
roundish-cuneate ; they are usually less lobed than in the Venus- 
hair, and have rather short oblong or somewhat lunate involucres. 
The credit of the discovery is in great part due to Mrs. Dr. Barnes, 
of Syracuse, who found in a conservatory living plants which were 
brought from Florida by Mr. Christian Beh, who discovered them in 
March, 1877, growing about the opening of a “sink-hole” on the 
plantation of a Mr. Williams near Ocala. Mrs. Barnes, on seeing 
the plants, suspected something different from A. Capillus-Veneris, 
and sent me at first an imperfect frond, which I doubtfully referred 
to Ad. tenerum. In afew days she obtained much finer specimens, 
which she sent me, and herself pointed out the important distinguishing 
character of the articulation at the base of the pinne. It now appears 
that the same species was noticed on the Halifax river a long time 
ago by Mr. S. N. Chamberlin, who showed the plants to Miss Mary 
C. Reynolds in May, 1877. Miss Reynolds collected specimens at 
that time, and reported the fern as 4d, Capillus-Veneris in the BULLE- 
TIN of Sept. 1877, (p. 176), where she so well describes the habit of 
A. tenerum that I ought to have recognized the species from what she 
says about it. I received some of her specimens very lately from 
Mr. C. E, Faxon. Mr. Davenport has specimens from Ocala, 
gathered in 1878 by Mr. Shockley; and to-day I have before me a 
very fine and full set of specimens collected the present month at 
Ocala by Capt. J. Donnell Smith, who, with his. characteristic 
generosity, has sent me his whole collection of Ocala Ferns to choose 
from for my herbarium. 
Capt. Smith has sent with the Adiantum, fine series of specimens 
of Asplenium myriophyllum and A. Jirmum, Pteris Cretica, and a 
Polypodium which seems to be so’ nearly intermediate between P. 
pectinatum and P. Plumula, that I cannot at once decide what todo — 
