Recent Literature. 265 
The accompanying map shows, also, the former and recent dis- 
tribution of Salix polaris, which, in connection with the other 
facts mentioned above, may give us important hints as to the migra- 
tion of plants. It is to be hoped that Professor Nathorst will soon 
give us the promised work upon the distribution of these plants. 
‘And similar researches are highly recommended to the paleobotanists 
of this country. 
FRIDOLIN Krasser: Zhe Rhetic flora of Persia.* 
It was not until the year 1858 that the. fossil flora of Persia was 
investigated, when Dr. Goebel, as a member of the Khanikow- 
expedition to Chorassan, had the opportunity of making some col- 
lections in that country. These were studied by Dr. Goeppert. 
While Dr. Goebel collected in the province Asterabad in eastern 
Persia, visited Tietze, several years later, Hif near Kaswin and the 
mountain Siodscher, and Dr. Wahner made extensive collections on 
the Polak-expedition, discovering plant-bearing deposits near Rud- 
bar and Sapuhin. 
The Persian fossils from these localities occurred in a formation 
consisting principally of a greenish or sometimes reddish sand- 
stone, the age of which, judging from the flora, seems to be iden- 
tical with the Rhetic formation. 
The author gives a complete list of works, published upon this 
Persian flora, the most important having been written by Goeppert, 
Polak, Schenk, Sturr and Tietze. He also mentions the most in- 
teresting fossil plants that were collected by the above mentioned 
explorers, and gives, finally, a full account of a very large collec- 
tion, made recently by Dr. Rodler near Sapuhin at Kaswin, and 
presented to the Vienna Museum by the late Dr. Polak, court-sur- 
geon of the Shah. It is especially from this last collection, that the 
age of the formation has been ascertained, and the specimens seem 
to give a more complete illustration of that flora, than any of the other 
Persian collections. We find in the list a few Archegoniata: Equi- 
setacee and Filices. Among the genera of these families are Zgu- 
setum, Phyllotheca, Asplenium, Bernouillia, Clathropteris and others. 
The Cycadee@ are represented by Podozamites, Otozamites—of which 
o the science—and such genera as 
O. Polakii is described as new t 
*** Ueber die fossile Flora der rhatischen Schichten Persiens.” (Sitzungsberichte 
d. K. Akad, d. Wissenschaften, Wien. vol. 100, 1891, 20 p.) ~ 
