LEPTODORA HYALINA. 295 
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LEPTODORA HYALINA. 
BY WALTER GRAHAM, F.R.M.S5., PRESIDENT OF THE BIRMINGHAM 
NATURAL HISTORY AND MICROSCOPICAL SOCIETY. 
About three weeks ago a few members of the Birmingham Natural 
History and Microscopical Society visited a pool in the neighbourhood of 
Olton, which, being private property, is not often examined. Four of the 
party proceeded in a boat to endeavour to ascertain what treasures the 
water contained. The first dip caused no small excitement. A bottle of 
water, apparently containing diluted pea soup, was eagerly examined by 
one after another, for among the masses of a minute alga (Clathrocystis 
eruginosa) were swimming sundry apparently animated chips of thin glass. 
What was this translucent creature? was the question. The glass larva 
was speedily dismissed, but even the class to which the unknown capture 
belonged was doubtful, the best guess hazarded being that it was a larval 
form of some Entomostracan. Specimens were carefully secured for 
examination under higher magnifying power than pocket lenses afforded, 
and this examination revealed the fact that the mysterious stranger was 
no larval form, but a fully-developed Entomostracan, both eggs and young 
being detected beneath the carapaces of some specimens. But still its 
name was wanting. ‘“ Baird,” and the ‘“Micrographical,” and “ Pritchard” 
failed us, but Professor Ray Lankester came to our aid, for, on having 
specimens submitted to him, he pronounced it to be Leptodora hyalina, &% 
species new to Great Britain, though found in Sweden and Germany. 
Curiously enough the same “ dips” which gave us Leptodora gave us also 
another new British species, which is described at page 217. 
In the hope that other students of this class may meet with 
Leptodora, the following imperfect description is given, which, with the 
help of the accompanying plate, (Plate V.,) drawn by my friend, Mr. H. 
EB. Forrest, may enable them to identify the crystalline stranger. 
Leptodora belongs to Baird’s Legion Branchiopoda, OrderII., Cladocera, 
Family I.,Daphniade. The head is elongated, not beaked. Superior 
antenne long, and studded with sete. The inferior (or propulsive) 
antennex are large and very powerful, producing a motion similar to that 
of aman swimming. The first joint occupies fully half the length of the 
antenna. From it two equal branches proceed, which are four-jointed, 
and are studded with sete, while the first joint is smooth. On each side 
of the head, immediately under the eye, is a small organ covered with 
cilia. The feet are ten in number, close together, and setaceous. 
The carapace is extremely hyaline, divided into seven segments ; the 
tail is produced into two curved extensions resembling that of an earwig, 
excepting that in Leptodora these extensions are furnished with long, 
slender set. The body is long and narrow, and so translucent that the 
Rererences to Puate V. 
Fig. A._Leptodora hyalina, x 50 diameters. 
Fig. B.—Ditto, x 60 diameters. a, Pulsating vessel. b, Eye. c¢, Organ of hearing (?) 
dito5, Feet. d@6, Superior antenne. ¢, Tube or intestine. f, Inferior antenne. 
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