1901] MICROSCOPICAL JOURNAL. 231 
stance. I should be glad of information on this partite. 
—R. T. Ditchfield. 
This parasite is Argulus foliaceus. The following 
description is from the “Micrographic Dictionary”: “A 
genus of Crustacea, of the order Siphonostoma and 
family Argulidae. Characters: Carapace membranous; 
covering the cephalo-thorax like a shield; antennae 
four, short, concealed beneath the carapace, anterior two- 
jointed, terminal joint hooked; posterior four-jointed ; 
rostrum acuminate; five pairs of legs, the place of the 
first (6th) pair being occupied by two suckers; second 
pair short, five-jointed, the two basal joints spinous, the 
last joint with two small hooks; the last four pairs of 
of legs two-cleft, and furnished with ciliated filiform 
processes.” The Argulus is usually found parasitic on 
fresh-water fish, and is often called the “fish-louse.’ "—C, 
Folkard. : : : 
This is certainly Argulus foliaceus. Itisa ldwesiollt 
friend of mine. I took a careful drawing of one some 
time ago. I have fallen across this parasite several times 
since. Science-Gossip gave a figure of one some years 
ago, which was afterwards reprinted in Taylor’s ‘“‘Half- 
hours in the Green Lanes.”’ It is found on all kinds of 
fresh-water fish, and Taylor says it is also found on: wae 
tadpole.—Chas. D. Soar. 
There is an illustrated article on ‘‘Fish-lice,” by Mr. F; 
Noad Clark, at p. 324,8.-G., Vol. V., N. S., describing 
the life-history of Argulus. | ’ : 
Mountine Rotirers AND Hyprozoa.—I have never 
seen any successful mounts of rotifers. Can anyone in- 
struct me how to do it? Fresh water is full of beautiful 
creatures, but we seldom see them preserved as slides. 
My method of mounting rotifers has been to drop one per 
-cent solution of osmic acid onto the slide, and close the 
cell.— William H. Burbidge. 
