Stiidii's on ninriiii; Ostracods 



4.^5 



one. 



which, like the preceding joint, is rather powerful and is to be denoted as a basale. 

 Distally on the anterior side the protopodite has indications of two endites. Distally of 

 these and in front of the part that has just been termed the exopodite there is a rather strong, 

 but short and unjointed, process, furnished with powerful muscles and bristles, a process which, 

 on account of its position, is perhaps to be regarded as homologous to the process in the 

 family Polycojndae that was termed by me above the endopodite; cf. fig. IV: 6. The morpho- 

 logical value of this last part seems to me, however, rather doubtful. Does it perhaps belong 

 to the protopodite or the exopodite? 



The families Cypridae, Darmmdiclue, Nesideidae, Cytheridae and Cytlierdlidae: In these Cypndac, Darwm- 

 families the fifth limb shows such far-reaching agreement with the same linib in the Halocypridae "^"j"'' J^'«'<'eirf<'<'. 

 that one can show with a fair degree of certainty which parts of this appendage in these families r',,'iZ'remle. 

 correspond to the different parts of the same organ in the last-mentioned group. 



■ij;. V. — Posiliuii of lln; vibratory plate on tin; fifth acid -si.vlii liiiiljs. I. I'iftli liiiiii of Sclcrochilux conlorlim 

 (A. M. Norman), ?. 2. Sixth limb of Nesidea frequens (G. W. MCller) (From G. \V. Miiller. I89'i). 



The vibratory plate, which is more or less completely reduced in the C y t h e r i d s and 

 a number of C y p r i d s, is certainly homologous with the same organ in the H a 1 o c y- 

 ]) V i d s and, according to the explanation made use of above, it is consequently to be 

 denoted as an epipodial appendage. It is situated at different places on the protopodite, some- 

 times distally*, sometimes proximaUy (cf. tlie accompanying fig. V: 1). The protopodite is 

 unjointed. Distally anteriorly it has sometimes an unjointed process pointing forwards and 

 inwards, which, according to its position, is to be considered homologous to the part that 

 was denoted as the endopodite in the preceding family. This part is in most cases more or 

 less completely absent in Nesideidae and Cytheridae. The backward pointing, rod-shaped, 



* TIr' siuglu brisllr on llic po^lorioi' sidt- of thu protopodili' of Ihi.s limb in some C y p r i d .s (si-u fig. l\: 7) 

 has tx-rtaiiily been explained by nie as a rediieed form of the vibratory plate, but this assumption is, however, far 

 from certain. This uncertainly is perhaps best illustrated by the sixth limb oS Ci/iherella ^i on this we find on the 

 posterior side of the prolopodile not oidy a well-developed vibratory plate, bnl .ilso some single bristles. Cf.. for 

 instance. C. sordida, (i. W. Mi i.i.lii. isy'., pi. M. fit;. .">. 



