Bibliographical Notice. 493 
come to his notice, but the paper was not published until this year 
(Zool. Gart. Frankf. 1865, pp. 50-59, 89-97). Dreissena poly- 
morpha is, according to Hr. Merian (/. c.) accompanied by Neritina 
fluviatilis in the Upper Rhine, where it never occurred before. The 
Recorder is enabled to confirm this by a communication from Prof. 
Braun, who says that it was not found in the Rhine near Carlsruhe 
some twenty years ago”’ (pp. 191-192). 
In the second volume of the ‘ Record,’ pp. 216-217, we have the 
following additional particulars on this most interesting subject :— 
“Martens, E.v. Hine eingewanderte Muschel. Zoolog. Gart. 
Frankf. 1865, pp. 50-59, 89-95. Dreissena polymorpha was not 
known in the northern and western halves of Europe some forty 
years ago. The numerous treatises on the mollusk-faunas of these 
countries published at the close of the past and in the first two 
decades of the present century do not mention it. All at once it 
was observed for the first time in tributaries of the Baltic, the 
Niemen and Weichsel, in the year 1825, in tributaries of the Elbe in 
1828, in the terminal branches of the Rhine in 1826, and in England 
in 1824. Several direct observations, and the comparison of the 
localities and times in which it has been observed for the first time 
in the several countries, establish the fact that it has been introduced 
into all those parts of Europe, along artificial, navigable canals, by 
means of ships or timber, and even across the Channel to England. 
The belief that it was observed already towards the close of the past 
century in south-western Germany is founded on a very superficial 
description of a shell by Sander and contradicted by the negative 
evidence given by Prof. Alex. Braun for the years 1824-46, and by 
Hr. Gysser for the present time, both agreeing in never having met with 
Dreissena in that part of Germany. As regards the rivers near to the 
Black and Caspian Seas, no reliable or sufficiently complete record 
of their faunas has been preserved from the commencement of this 
century; and there is consequently no reason to think that a 
recent migration has taken place into the Danube and the rivers of 
Southern Russia. At present it inhabits nearly all the tributaries 
of the Baltic, the Elbe upwards to Halle, the Rhine upwards to 
Huningue, the rivers of northern France, including the Loire, the 
British Islands, Hungary, a part of European Turkey, and almost 
the whole of Russia. It is very desirable that the attention of 
conchologists should be directed to the further advance of this shell, 
and that accurate statements should be made as regards the time 
at which it first appears in the lists of local faunas, not having been 
mentioned by previous accurate observers. This species is really a 
freshwater shell; it does not live in the Baltic itself, but only in the 
brackish water near the mouths of the rivers. The breakwater 
leading to the lighthouse at Swinemtinde, for instance, is occupied 
on the river side by Dreissena, on the sea side by Mytilus edulis. 
“Hr. Jackel, Hr. C. Staude, and Dr. Fr. Buchenau have con- 
tributed further observations on this subject in the same journal, 
pp. 196, 228, and 278, in which they state that this shell is found 
at present in the Weser and in the Bavarian tributaries of the Main, 
Ann. & Mag. N. Hist. Ser. 3. Vol. xvii. 34 
