1884.] | Zoology. ABS 
their capture he employed a net of fine muslin of a conical form, 
attached to a ring about 50° in diameter. The bottom of the 
net presents a contracted opening, like that of a “ well,” which 
opens at the middle of a much smaller net made of silken sieve- 
cloth, with very fine meshes. This latter is attached to a ring, 
equilibrated by a fragment of cork. This net of silken gauze 
oes not injure the animals at all, and it captures at least twice 
as many as the glass bottle which some naturalists substitute for 
it. It is easy to understand, in fact, that the impermeable walls 
of the bottle compel the water to turn in its interior, and cause 
eddies, which carry out a considerable proportion of the captured 
animals. 
With creatures so active and so difficult to observe alive under a 
high power, it is of great importance to have a process which 
enables them to be fixed instantaneously in their natural attitude 
before they have had time to withdraw into their test, and which 
preserves faithfully the details of their structure. 
Dr. Fol tried the various reagents most in vogue without at- 
taining his purpose. With weak osmic acid he did not succeed 
in preserving the cilia of the peristome; and with a stronger 
dose the body became absolutely opaque; in both cases there 
was always a strong contraction. 
Acetic acid, chromic acid and picro-sulphuric acid only gave 
him a fixation which was too slow, so that the animal died con- 
tracted in the bottom of its test. Finally he “succeeded with a 
reagent which is not employed in histology, perchloride of iron ;” 
by its means he has obtained a considerable number of specimens 
of various species, fixed in a state of full expansion. These sub- 
Jects, washed with alcohol and treated with gallic acid, present a 
brown coloration which is especially localized upon the nuclei, 
and renders them very visible ; the other parts of the animal ac- 
quire a light-brown tint, which renders them easy to see.— Fourn. 
Roy. Microscopical Society. | 
ound on the coast of Northumberland almost every stone 
in all directions by different species of Clione. Finally, 
