108 BRITISH ENTOMOSTRACA. 



The second has three plumose setae springing from its 

 inner edge, each arising from a small projection, and 

 furnished with a joint about the middle of tlieir length ; 

 and one short simple spine from outer angle at the an- 

 terior extremity. The third has seven similar setae, four 

 on the inner edge, and three at the extremity, besides 

 one short simple spine at the outer angle. The inner 

 branch has only two joints, the first much the longer of 

 the two, and having at its extremity or inner edge one 

 short simple spine, and one long seta, the second or 

 terminal very short, and having four long plumose setae 

 from its upper edge. 



The mandible (t. XIII, f. c; t. XII, f. 3 a,/) is similar 

 to that QiBaphiia ScJicefferi, and has a row of cutting teeth 

 on its edge. The labrum (t. XII, f. 3 a, j/) is like that of 

 Daphnia, and is provided with a strong muscle. The 

 intestinal canal is large. The oesophagus is in form of a 

 narrow, slightly-curved canal, which terminates a little 

 below the eye in a large cid-de-sac, the commencement 

 of the stomach (t. XII, f. 3 a, *?). There does not appear 

 to be any organ corresponding to what has been described 

 in Daphnia as the cacum. The feet are six pairs in 

 number, and differ from those in the Daphnina, and also 

 from each other. Tlie first pair (t. XIII, f. d) consists of a 

 main stalk of tvA^o articulations, one of which has four 

 setae, the other seven. From the inner edge springs a 

 large branchial plate provided with about thirty filaments, 

 and from its upper part a smaller plate arises furnished 

 with nine or ten short filaments, and one longer and 

 plumose. The four succeeding pairs are more like each 

 other, but differ somewhat from the first pair. They 

 each (t. XIII, i-e,/) possess a small triangular plate fixed 

 upon the edge of the main stalk, and taking the place. of 

 the setae which are found in the preceding. The smaller 

 branchial plate is shorter, broader, and square-shaped, 

 and the branchial filaments of both plates are shorter. 

 The sixth pair (t. XIII, f. r/) differs from all the others. 

 Each foot consists of three articulations, each finmished 



