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six inches in length, attached at the bottom of the water to stones or aquatic 
floating plants : examined under the microscope', these filaments present segments 
nearly as wide as they are long. After the emission of the colouring matter, the 
filaments become of a clear green ; a portion of the tube is emptied of the endo- 
chroma which filled it, forming masses of a certain consistence, often separated at 
small distances. In the empty portions, no traces of the segments can be distin¬ 
guished on the external tube. 
The singular coloration produced by this Oscillaria takes place almost instantly 
on its being gathered ; and it is impossible to transport any mass of it without 
their becoming immediately decomposed. If specimens preserving their original 
colour are required, they must be prepared on mica, or paper, in the water in 
which they were found at the moment of their being gathered. In all cases, on 
their becoming dried, it colours paper with blue zones; it also exhales a sharp 
ammoniacal odour, very different from its congeners. 
De Bribisson and Lenormand discovered this Oscillaria in the month of Sep¬ 
tember, 1825, in the River Orne, near Falaise ; it reappeared in 1S28, since 
which it was vainly sought for, when again this year it was abundantly found, in 
the month of July, in the same river. 
Specimens have been forwarded to Mr. Duby, while publishing his JBotanicon 
Gallicum, mentioning the phenomenon of coloration above stated, which his de¬ 
scription does not correctly convey in these words :— Filamentis : demum lilaci- 
nis aquam pur pur io et violctceo tingentibus. 
Other Oscillarise imgart the purple or blue tinge or water on their decomposition, 
but we have never observed the two shades existing at the same moment, as in the 
species now described. 
Mr. Leclencher has addressed de Blainville on the subject of the Spi- 
rula . He has succeeded in taking, on the Bar of Senegal, the animal inhabiting 
that mollusc, in a sufficiently perfect state to enable him, by a comparison with 
others possessing the mutilated parts, to complete a description of the whole. He 
has observed that the Physalioe feed commonly upon these animals, which ac¬ 
counts for the number of their shells and the rarity of the animal in a living state. 
In addition to the description already given by naturalists, Mr. Leclencher adds, 
that, independent of the lateral lobes which terminate the animal, two Jins may be 
distinguished, so placed that only a small portion of the shell is exposed. The 
eyes appear large, and enclosed in a cartilaginous orbit. The lower part of the 
neck presents the funnel shape usually seen in cephalopids. 
