24 BRITISH ENTOMOSTRACA. 



except that the fingers or claws successively become shorter 

 and broader, while the branchial plates and oval sacs in- 

 crease in size in the same proportion. These nine pairs 

 of feet are described by Schceffer under the name of claw- 

 bearing branchial feet. The tenth pair of the branchial 

 feet differ materially from all the rest (t. I, f./), and as 

 no males have as yet been met with^ we can only describe 

 them as they exist in the female. The basilar portion, 

 consisting of three joints, is not distinctly seen, being 

 merely a membranous expansion, although aa'c trace the 

 same number of claws and other bodies described in the 

 preceding feet, but shorter and broader, whilst the tri- 

 angular branchial plate and oval sac have assumed the 

 appearance of two circular plates, one a little larger than 

 the other, and attached to its fellow by a kind of hinge- 

 joint, which allows them to be folded over upon each 

 other, thus forming a kind of capsule. In place of being 

 transparent and colourless, like the branchial plates in 

 the other feet, these are full of little round spots, like 

 grains, of a bright red colour, and which, when examined 

 by the lens, are seen to be eggs. This pair of feet may 

 therefore be considered as a sort of external ovary, — 

 Schceffer calls them ovarian feet. In the centre of the 

 membranous basilar portion we observe a small, reddish 

 spot, surrounded by an elevation in which there is an 

 opening that Avill admit of a small bristle being intro- 

 duced. Schceffer considers this to be the situation of 

 the organs of generation. The eleventh (t. I, f. y) and 

 succeeding pairs of branchial feet, assume a different ap- 

 pearance from that of the ten preceding. The basilar 

 portion is much shorter, and apparently consists only of 

 one joint. The external finger, or claw, is much larger, 

 and semicircular, but of a membranous structure, and 

 the others, though of the same number, are shorter and 

 broader than the corresponding appendages of the other 

 feet. The oval sac is rather narrower and more elongated, 

 and the branchial plate is more rounded and broader, 

 while on its external edge, instead of the numerous fine 



