412 Rev. A. M. Norman on Acantholeberis, Lilljeborg, 



very large, stout, and powerfully muscular. Both branches very 

 short, the separate articulations being scarcely longer than they 

 are broad, and the total length of the branches barely exceeding 

 the width of the bases of the enormously developed peduncles. 

 Upper and four-jointed branch terminating in three plumose 

 setae and a long spine, which equals two-thirds the length of the 

 basal portion of the setae. Lower and three-jointed branch 

 having a seta at the extremity of the first and second joints, and 

 three setae and a spine at the termination of the third joint. 

 The setae of the first two joints do not differ materially in cha- 

 racter from those at the extremity. The last portion of the 

 abdomen (PI. XL fig, 7) is in the form of a somewhat flattened 

 semicircular plate, margined with large spines. The claws are 

 large, produced, simple, and cylindrical. Just below their base 

 is a cluster of small spines, which are succeeded by some still 

 smaller spines; behind these the spines increase in size, becom- 

 ing both numerous and large. The abdominal setae are long and 

 slightly plumose. The ventral edge of the carapace is fringed 

 with plumose setae (fig. 8) ; but at the posteroventral angle 

 these setae become much longer, assume quite a spine-like cha- 

 racter, and bear, as it were, smaller spines attached to one side 

 (fig. 9). The entire animal is of a brilliant crimson colour. 



This Daphnian is remarkable alike in history and in habits. 

 On examining with a hand-lens the vegetable matter in a 

 bottle of water brought home from a clear pond which had 

 been cut out of the limestone rock, to contain water for the 

 supply of the engine at a now unworked colliery at Bishop 

 Middleham, in the county of Durham, a small blood-red Ento- 

 mostracan, which was lying upon its back in the water, attracted 

 attention ; and on further search, two more individuals were 

 found in the same bottle. They at once became a source of 

 great interest ; for A. sordida is the most helpless animal possible. 

 It is totally unable either to swim or to walk. The setae of the 

 antennae are apparently of insufficient length to confer the power 

 of swimming; and the feet in this family, though valuable 

 agents in respiration, are totally unfitted in their structure for 

 purposes of locomotion, and, indeed, being contained within the 

 carapace, could not by any possibility be used for the support of 

 the body. The animal therefore lies upon its back, kicking and 

 struggling, swinging to and fro its brawny arms (the posterior 

 antennae), and thrusting in and out of the carapace-valves its 

 largely developed and strongly spined abdomen in the vain 

 attempt [to push itself from place to place ; but the efforts, 

 though most vigorous, are of little avail, and its progress is 

 extremely slow. It is probably in consequence of these sluggish 



