ROT UR op Rear ek Oe) Sa es. oe ee eee Se NES Stone | aad yen ere MEE Ise sen 5 
TTS ree he Cee ee eee Wane an oe pentane Oyo i 
bak Peete = LS 
1913] CURRENT LITERATURE 2509 
4 cavity down to the chalaza, as in the Rosaceae, but for some reason, possibly 
as a result of the peculiar mode of life shown by these plants, the outgrowth 
process no longer occurs, so that the empty ‘“ Pseudoembryosack”’ remains. 
The Crassulaceae are thus regarded as transitional forms between the Podoste- 
maceae and the Rosaceae.—LESTER W. SHARP 
Antarctic lichens.—In 1909 DARBISHIRE” reported on the very extensive 
collection of lichens secured by the Norwegian polar expedition of 1898-1902 
d ANSEN. In connection with this report it was shown that from the 
region including Arctic America, Greenland, Spitzbergen, and Iceland about 
500 lichens have been recorded. A similar report has now been published by 
DarsisHirE® for the antarctic region, based upon the collection brought 
back by the Swedish antarctic expedition of 1901-1903. There are now 
known 534 lichens from the general antarctics (subantarctic America, South 
Georgia, and the true antarctic region), 145 of which were secured by the 
_ expedition, 34 of them being new species. The true antarctic region contains 
106 known lichens. It is an interesting fact that the relation of arctic to 
alpine lichens is much greater than that of subantarctic American species to 
those of New Zealand. It is further obvious that the similarity of subantarctic 
to arctic species is less striking than that of antarctic to arctic species, 43 per 
cent of the antarctic lichens being found in the true arctics and not in temperate 
regions. 
The new species are distributed among 17 genera, Lecidia and Buellia 
having 5 each; Pertusaria, Aspicilia, and Verrucaria having 3 each; Bacidia, 
. re eee Parmeliella having 2 each. The remaining genera, each repre- 
by one new species, are Biatora, Thelotrema, sissy Caloplaca, 
enc Parmelia, Rinodina, Acarospora, and Chaetomium.—J. M. C. 
A new Williamsonia.—Srwarp® has studied petrified material of a 
Williamsonia from the Jurassic of Scotland, to which he gives the name W. 
Scotica. It proves to be an exceedingly interesting and suggestive form. 
. _ The most striking vegetative feature is the replacement of the usual scales 
(tamentum) of the Bennettitales by an abundance of very long hairs, such 
occur on Dioon edule and other living cycads. The sections of the stro- 
bilus, the first obtained of a Wéilliamsonia, are of special interest. The 
isporangiate character is problematical, since no stamens were evident and 
Natuorsr has shown that some species of Williamsonia were monosporangiate. 
en, 
*7 DARBISHIRE, Otto V., Lichens collected during the second Norwegian polar 
aR in 1898-1902. Publ. Soc. Arts and Sciences Kristiania. 1909. 
, The lichens of the Swedish antarctic expedition. Wiss. Ergebn. 
: Sea Sudpolar-Exped. IQOI~1903. 42 no. 11 (pp. 73). pls. 3. 1912. 
*9 SEWARD, A. C., A petrified Williamsonia from Scotland. Phil. Trans. Roy. 
Soc. London B. 203:101-126. pis. 9-12. 1912 
