1887.] 



ON CYCLESTHERIA HISLOPI. 



25 



projection, extending but little if at all beyond the tip of the 

 epipodite. The last pair of legs (Pl. V, figs. 4, 5, p l& ) are very 

 small, though still exhibiting all the principal parts. The very 

 much shortened endopodite has, besides the well-developed coxal 

 or maxillar lobe, but three lobular expansions, each provided with 

 only a small number of setæ. The exopodite is nearly oval in 

 form, with the upper prolongation very small, not reaching by 

 far to the tip of the epipodite, and the marginal setæ rather 

 unequal in length and number about 19 in all. 



As with the genus Limnetis, only the first pair of legs in the 

 male are modified to grasping organs, whereas in Estlieria, and 

 also in Limnadia, the 2 anterior pairs of legs are provided 

 with well-developed hands. The prehensile character of the 

 first pair of legs in the present form is even quite distinct 

 in the young before their escaping from the incubatory cavity 

 of the parent (see Pl. VIII, fig. 1). As to the structure of these 

 legs (see figs. 2, 3), it seems on the whole to agree pretty well 

 with that described in IÅmmtis, the three outer segments of 

 the endopodite being peculiarly modified, so as to form together 

 a strong grasping organ, or hand. The first of these segments 

 is very much dilated and somewhat triangular in form, the outer 

 edge being strongly curved at the base, the inner projecting 

 as a rounded lobe, setiferous along the upper part of the edge 

 and armed at the tip with two knob-shaped processes. The suc- 

 ceeding segment has assumed the form of a strong curved claw, 

 obtuse at the tip and bearing outside a row of five slender setæ. 

 This claw admits, by the aid of a strong muscle joining it 

 at the base, of being impinged against the projecting lobe of the 

 preceding segment, and is armed internally at the tip with two 

 or three knob-like processes, similar to those on the preceding 

 segment and meeting it when the hand is shut. The last segment, 

 finally, has the form of a slender digitiform appendage, proceeding 

 from the outer side at the base of the claw and provided at 

 the end with about eight setæ. 



The legs are moved by several muscles passing from the 

 trunk and penetrating the basal part of the endopodite. Thus, 



