Miscellaneous. 309 
its rapid motions, in seizing its food, which it is believed it does 
by ‘striking across the course of what it supposes to be its 
flying prey,”’—thus almost proving that its pursuit is more 
under the influence of sight than of taste or smell. 
Couch, in his recent beautiful work, says that it will never 
attempt to seize that which seems without life; hence the object 
of the fishers is to cause the boat to be influenced by an amount 
of motion which shall resemble a living object. The boat must 
therefore be always under sail, and in a sufficient breeze to 
ensure any amount of success. 
MISCELLANEOUS. 
Note on the Genera Amphipeplea and Assiminea. 
By J. Gwyn Jurrreys, Esq., F.R.S. 
Dr. E. von Martens, in his interesting “ Conchological Gleanings ” 
(Ann. & Mag. Nat. Hist. ser. 3. vol. xvii. p. 211), has referred to 
the description, in my work on British Conchology, of the shell of 
Limnea involuta, in comparison with L. glutinosa and L. auricularia; 
but he seems to have overlooked the sectional character which I 
there gave of the first two species, viz. “extremely thin and fragile.” 
Nor has he quoted exactly the words which I used in describing DL. 
glutinosa. He would also have found that Lapland was recorded 
by Nylander as a station for L. glutinosa, Pau by Mermet, and the 
south-west of France by Des Moulins and many other writers. J 
thank him for having called my attention to the two localities in the 
Mediterranean province. The genus Amphipeplea cannot be sepa- 
rated from Limnea, if Aplewa remains united with Physa. 
Assiminea is undoubtedly marine and pulmonobranch, as I shall 
be prepared to show in the course of my work. The dentition of 
A. Grayana and A. litorea is delineated in the ‘Annals and Maga- 
zine’ for February 1859, pl. 3. figs. 12 & 13. 
March 24, 1866. 
On the Existence of a Third Membrane in the Anther. 
By. A. CHatin. 
Botanists generally believe that the anther consists only of two 
membranes, named, since the time of Purkinje, the evothectum and 
endothecium. But Meyen and Schleiden observed in certain young 
anthers the tissue which corresponds with the third membrane ; 
they seem, however, to have regarded it as part of the endothecium of 
Purkinje. The author states that there is no doubt of the existence 
of a third membrane interior to the endothecium or membrane 
with fibrous cells ; it forms a sort of interior epidermis, and should 
be called the endothecium, the membrane which received that name 
from Purkinje being the mesothecium. 
Evolution. —The third membrane always exists at a certain stage 
