1896.] Botany. 669 
, bears zoospores in the conceptacles and not oogones, hence it must be 
placed in the Zéosporine. 
The treatment of the Zoosporinz is practically that of Kjellman in 
Engler and Prantl’s, Pflanzenfamilien, except that the genera Litho- 
derma and Arthrocladia are placed in families by themselves, instead 
of in the Ralfsiacee and Desmarestiacee respectively, and that De Toni 
has included five small, mostly, monogeneric families, the Phaothamni- 
ace, Pheocapsacee, Hydruracee, Chromonodacee and Chromophyto- 
nacee not mentioned by Kjellman. In All the Zoosporinz except the 
above families the zoospores as far as known are laterally biciliated and 
are borne in some form of zéosporangia. In these families there are 
no zoosporangia and in at least a part of them the zoospores are not 
laterally biciliated and in general their relationship seems to be with 
the Chlorophycee. It seems more natural to place them, as Wille has 
with some of them, in the Chlorophycee next to their closely related 
genera. 
The book is well arranged; priority in class, ordinal and family. 
nomenclature is strictly observed. It will be indispensible to the spe- 
cialist in this line and a great help to the general student.— Dr ALTON 
SAUNDERS. 
The Flora of the Black Hills of South Dakota.—In a recent 
number of the Contributions from the U. 8. National Herbarium (Vol. 
III, No. 8; issued June 13, 1896), P. A. Rydberg gives the results of 
his explorations (in 1892) of the Black Hills of South Dakota. The 
report, which includes about eighty pages, includes the following, viz. : 
Itinerary, Geography, Geology, Altitudes, Precipitation and Tempera- 
ture, Floral Districts, General Remarks, and the Catalogue of Species. 
The plates are a Map of the Black Hills, Aquilegia brevistyla, Aqui- 
legia saximontana and Poa peeudopratensis. The floral districts recog- 
nized by the author are five, viz.: (1), the foothills and surrounding 
plains, (2), the Minnekata Plains, (3), the Harney Mountain Range, 
(4), the Limestone District, (5), the Northern Hills. 
In summing up his discussion of the vegetation of these districts the 
author says, “ From the foregoing can be seen what a varied flora the 
Black Hills have. There are found plants from the East, from the 
Saskatchewan region, from the prairies and table-lands west of the 
Missouri River, from the Rocky Mountains, and even from the region 
west thereof. In the foothills and the lower parts of the Hills proper 
the flora is essentially the same as that of the surrounding plains, with 
an addition of eastern plants that have ascended the streams. In the 
higher parts the flora is more ofa Northern origin, Most of the plants 
