grt] CURRENT LITERATURE 399 
under the title “Crataegus in Pennsylvania II” records 110 species of this 
genus from Pennsylvania, 79 of which are indicated as new.—R. SCHLECHTER 
(Rep. Nov. Sp. 8:561-572. 1910) under the title “Orchidaceae novae et 
criticae” has published 19 new species of orchids, several being from America; 
one new — (Platystele) is proposed, which is based on PirtTrEeR’s no. 201 
from Costa Rica.—J. K. Smatz (Torreya 10:230, 231. 1910) has described 
continues the ‘Flora portoricensis.”” The present fascicle contains the genera 
from Euphorbia to Verbena and includes a new species of Heliotropium (H. 
antillanum) from Porto Rico and Cuba, and a new variety of Jussiaea suf- 
Jruticosa L.—W. Wetncart (Monats. fér Kakteenkunde 20:161, 162. 1910) 
has published a new species of Cereus (C. cinnabarinus Eichlam) from Guate- 
mala.—R. S. Witxiams (Bull. N.Y. Bot. Gard. 6:227-261. 1910) in a second 
contribution on Bolivian mosses records approximately 200 species and vari- 
eties, and of these ep are ae as new.—H. L. Wrtson (Univ. Calif. Pub. 
Bot. 4:75-84. pis. 1 3. Ig10) in conjunction with W. A. SETCHELL has 
published a new wens ‘(Gracilariophite) parasitic on Gracilaria confervoides. 
The host and parasite have the same subordinal relationship——H. WINKLER 
(Bot. Jahrb. 44:497-571. 1910) has published the first of a series of articles en- 
= ) 
work of identification the author has been assisted by eminent specialists. 
About 45 new species are here described for the first time, and one new genus 
(Campanocalyx) of the passes is included.—H. Wo.rr (Rep. Nov. Sp. 
*524-526. 1910) under the title ‘‘ Umbelliferae novae I”? has described new 
species from Mexico and China.—Different authors (Kew Bull. 328-344, 368- 
371, 381-386. 1910) have published new species of flowering plants, chiefly 
from Africa but including several from Peru. One new African genus (Necep- 
nis belonging to the tribe Crotoneae of the Euphorbiaceae, is proposed by 
D. Pray. —J. M. Greenman. 
Algal coals.—The characteristic petroleum-yielding coals known as bog- 
head, cannel, etc., have been referred to an algal origin by RENAULT, BERTRAND, 
and Potonré, a view that has been more or less acceptable to our own students 
of paleozoic coals. The evidence of such an origin is the occurrence in such 
Coals, as well as in bituminous schists and oil-shales, of abundant ‘spherical 
or oval bodies, often arranged in layers,” these bodies being interpreted as 
colonial algae. They have now been investigated by JEFFREY,’ who devel- 
Oped a special technique to secure numerous and even serial thin sections. 
As a consequence, the structure and hence the nature of these bodies have 
been brought out with a clearness not heretofore possible. 
ao aaa 
* Jerrrey, E. C. , The nature of some supposed algal coals. Proc. Amer. Acad. 
46: 273-290. pls. 5. 1910 
