ON A. NEW ENTOMOSTRACON. S17. 
ON A NEW ENTOMOSTRACON. 
BY H. E. FORREST. 
A short time ago Mr. Thomas Bolton sent me some water from 
Olton Reservoir, containing, amongst other things, a curious 
Entomostracon, which he wished me to examine and draw. At the first 
glanc3 I saw that it was a form new to me, and forthwith set about 
drawing it. That done, the next thing was to find out its name, but 
vainly did I search through and through Baird’s “‘ Entomostraca”—it 
was not there. All that could be discovered about it was that it belonged 
to the Hutomostraca, order Cladocera, family Daphniade, and genus 
Daphnia. Baird describes seven species, viz., Pulex, Psittacea, Vetula, 
Schefferi, Reticulata, Rotunda, and Mucronata, but the one in question was 
none of these, and I have therefore the pleasure of describing it as a new 
species, unless it has already been described in some other work unknown 
tome. Every Naturalist, and especially every student of Entomostraca, 
will feelthat it is but a just and graceful tribute to the name of one who 
did so much good work for science at a time when very little was known of 
these little creatures, if this new species be dedicated to Dr. W. Baird, 
the author of ‘The Natural History of the British Entomostraca,” 
especially as no other animal is so named. I therefore christen it 
Daphnia Bairdii, if it has not yet received any other name. 
The appearance of Daphnia Bairdii in the microscope is irresistibly 
comic. It has an immense head which terminates upwards in a sharp 
point, exactly as if it were wearing a ‘“‘ dunce’s cap,” and in this its one 
goggle eye rolls about with an air of supernatural wisdom. Its body is 
transparent and almost colourless. It hasthe following characters in com- 
mon with the seven other members of the same genus :—Head produced 
downwards into a prominent beak, from the base of which spring the two 
very small, one-jointed, superior antenne (a.) The inferior antennz (bd) 
are large and powerful, two-branched, one branch three-jointed and bearing 
five sets, the other branch four-jointed and bearing four sets. It has five 
pairs of feet (c) all enclosed within the carapace. The following characters 
distinguish it from its congeners :—The valves of the carapace or shell are 
oval, transparent, nearly colourless, and the surface is marked with striz 
crossing each other obliquely. These markings are not nearly so apparent 
asin the other Daphniz. The head is very large (larger than in any other 
species) and almost an equilateral triangle. The lower extremity of the 
valves terminates in a long, sharp spine, which is finely serrated; the 
edges of the valves, too, are sparsely serrated to about half-way up. 
Length from top of head to extremity of spine, 1-20in. The individual 
drawn on Plate IV.is an adult female, and has within her carapace and 
behind her body a young one, almost ready to issue forth. This young 
one is seen edgeways, and it will be noticed that the triangular head 
is not rounded but flattened at the sides, like an admiral’s cocked hat. 
In young specimens the body is more rotund than in the adult, and 
the top of the head is not nearly so sharply pointed. Daphnia Bairdii 
does not appear to be very prolific, as I never saw more than two eggs in 
one female. The male I have not yet seen, though I have searched for 
it, and hope to obtain it eventually. Anyone desirous of seeing living 
specimens of this interesting animal can obtain them from Mr. T. Bolton, 
17, Ann Street, Birmingham. 
HH 
