Palaeontologie. — Algae. 
221 
only one bündle. The course of the sporangiophore bundles, especially 
important as the main argument for fixing the position of this cone 
in the Calamarian series, begins immediately above that of the 
bract-trace — at the same node. They pass outwards very obliquely 
through the secondary wood of the parent-bundle, ascending in 
contact with the bündle through half an internode, then redescending 
obliquely to enter the base of the sporangiophore. 
The sporangia were closely packed, so as to fill completely the 
space enclosed between the bracts and the axis. Their walls consist 
of a single layer of ‘buttressed’ cells, exactly similar to those found 
in Calamostachys. There is no indication of heterospory. The spores 
show two distinct walls, separated by an interval. 
The Author next discusses the affinities of the cone. He points 
out that the cones of the Equisetales and Sphenophyllales show 
many points of agreement. He concludes, however, that Palaeostachya 
has no character in which it in any way even appears to approach 
the Sphenophyllum group. He points out that Calamostachys may be 
structurally closer to Palaeostachya than is generally believed, and 
that strong doubt may be thrown on the view that the sporangio- 
phores of the former really represent independent whorls. It is 
more likely that here also the sporangiophore-traces really arise 
just above the bract-traces, and if this is so then the only important 
differences between Calamostachys and Palaeostachya are the absence 
of any considerable reflection of the sporangiophore-trace in the 
former and the possession of (approximately) two bracts to each 
sporangiophore. Thus, since stress should not be laid on these 
differences, Calamostachys and Palaeostachya should not be remotely 
separated. 
The author concludes that the petrified cone described here 
must be kept within the genus Palaeostachya as instituted by Weiss, 
so long as his Classification is adopted. The course of the sporangio¬ 
phore-traces may be added as a new generic character. 
Arber (Cambridge). 
Ostenfeld, C. H., Beiträge zur Kenntnis der Algenflora des 
Kossogol-Beckens in der nordwestlichen Mongolei, mit 
specieller Berücksichtigung des Phytoplanktons. (Hedwigia 
XLVI. 1907. p. 365—420. Taf. IX und eine Kartenskizze.) 
Das Untersuchungsmaterial ist von W. Elpatiewsky (Moskau) 
im Sommer 1903 in dem gropen See Kossogol in der nordwest¬ 
lichen Mongolei, sowie in Teichen und Flüssen der unmittelbaren 
Umgegend des Kossogol gesammelt hatte. Die Bearbeitung der 
Bodendiatomeen hat E. Östrup übernommen. Verf. legt hier die 
Ergebnisse seiner Untersuchung von ca 50 Plankton- bezw. Algen¬ 
proben, ferner einiger Schlammproben vor. Die Arbeit ist schon 
deshalb von besonderem Interesse, weil über die Algenflora von 
Inner-Asien wenig, über das Phytoplankton fast gar nichts be¬ 
kannt ist. 
Die vorliegenden Literaturangaben werden kurz referiert und 
die in Betracht kommenden 10 Werke angeführt. Ebenso werden 
die geographischen und hydrographischen Verhältnisse besprochen. 
Verf. teilt hier die Untersuchungsergebnisse von Elpatiewsky 
wörtlich mit. Eine Kartenskizze ist zum besseren Verständnis bei¬ 
gegeben. Aus diesen Untersuchungen ergibt sich, dass der Kosso¬ 
gol alle Charactere eines Gebirgssees hat: bedeutende Tiefe, klares 
