maxillae this part terminates with a delicate pellucid, and some- 

 what deflexed point. 



The 1st pair of legs (PI. Ill, fig. 8, PI. IV. fig 2), origi- 

 nating immediately behind the 2nd pair of max ill*, are rather 

 powerful and admit of being extended from the shell inferiorly. 

 They are composed of a short and thickish basal part and a 

 slender terminal portion, forming together a geniculate bend. 

 The basal part exhibits 2 indistinctly defined joints, the outer 

 of which is quite short and rounded. The terminal part forms 

 a 4-articulated stem, tapering successively to the end and hav- 

 ing at the tip an elongated, anteriorly curving claw. Of the 

 joints the 1st is by far the largest, equalling in length the 2 

 succeeding ones taken together, and bears at the end anteriorly *a 

 small seta. The 2 succeeding joints are nearly of uniform size 

 and both provided with a similar short seta. The last joint is 

 very small, quadrangular in form, and exhibits, on either side 

 of the base of the terminal claw, a very small bristle. The 

 claw is very slender, a little longer than the 3 outer joints 

 taken together and regularly curved in the outer part, which is 

 finely denticulate along the anterior edge. 



The 2nd pair of legs (PI. Ill, fig. 9, PI. IV, fig. 1), origi- 

 nating immediately behind and somewhat outside the 1st, are 

 never exserted from the shell, being constantly kept inflexed. 

 with the outer part generally curving upwards along the sides 

 of the body. They are composed of 4 joints, the 1st and 2nd 

 forming together an abrupt geniculate bend, the others almost 

 straight. The basal joint bears at the end both anteriorly 

 and posteriorly a very slender seta, and a similar but some- 

 what shorter one is also found attached to the anterior edge. 

 The 2nd joint is rather narrow, slightly inspissated at the extre- 

 mity and provided with a single slender seta originating from the 

 end posteriorly. The 3rd joint is a little shorter than the 2nd, 

 somewhat instricted at the base and provided with a delicate seta 

 about in the middle of the posterior edge; the extremity of this joint 

 juts out posteriorly as a short thumb-like projection. The last 

 joint finally, is very small and not very distinctly defined from the 



