On Megalocypris princeps. 15 



The caudal rami (fig. 17) are very movably articulated 

 to the tip of the abdominal part of the body, and admit of 

 being suddenly projected from the shell, thus assisting in the 

 movements of the animal. When at rest, they are extended 

 anteriorly, and may be found more or less closely applied 

 to the ventral face of the body, in which case their 

 extremities are received between the bases of the legs. 

 They are very slender and elongated, almost equalling in 

 length 1 /3 of the shell, and are slightly flexuous, tapering 

 gradually towards the tip. At the tip each ramus carries 

 2 claws and 2 setæ, the one issuing in front of the claws, 

 the other at some distance behind them. The claws are 

 rather feeble and but very slightly curved, both minutely 

 spinulose along the hind edge. The distal claw, as usual, 

 is the longer, though scarcely exceeding in length 1 /3 of the 

 ramus. Of the setæ the apical one is rather strong, almost 

 spiniform, and about half as long as the distal claw. Along- 

 the lower, or more properly dorsal edge af the ramus a 

 very fine ciliation may be observed. , 



Of inner organs, the capacious intestine may be faintly 

 traced through the skin, being, as in other Cypridids,. 

 divided into 2 sharply defined divisions, the anterior of 

 which sends off to each side a large cæcal tube entering 

 the corresponding valve between its 2 lamellæ. These cæ- 

 cal tubes, or so-called liver-sacs, are easily observable, on 

 viewing the shell from the outer side (see figs. 1 & 2) r 

 extending diagonally along the posterior part of each valve. 

 Just above them, in the female, the ovarial tubes are located, 

 likewise received between the 2 lamellæ of the valves. 

 They were in the specimen examined (fig. 1) still rather 

 short, with only very small ovarial cells in process of 

 formation. In the male these tubes are replaced by the 



