TERRESTRIAL ISOPODA OF NEW ZEALAND. 113 



The pleopoda present the usual features, and all consist of a short basal portion or 

 protopoclite, from ^vhich spring the endopodite and exopodite ; of these the endopodite 

 is entirely branchial and has its margins perfectly free from seta), while the exopodite; 

 appears to be mainly opercular and usually has its margins more or less fringed with 

 plumose sette. It will be convenient to descril)e the [jleopoda of the female first, aud 

 then to point out the special modifications in the male. 



The first j)^coj)od has the protopodite short and Iji'oad, rouglily rectaiignkir l)ut 

 narrowing a little externally ; on the outer side it bears a small rounded appendage with 

 margins free from setae, which appears distinct from the rest of the protopodite though 

 not distinctly separated by any suture or articulation. This appendage, which is found 

 on the first and second pleopoda of both sexes, is perha})s to be looked upon as an " epi- 

 podite" ; it will, at any rate, be convenient to refer to it by this name. The exopodite 

 issubovalin shape and much larger than the endopodite ; its margin bears a few irregular 

 plumose setae. 



The second ijleopod of the female closely resembles the first, but is slightly larger ; 

 from the centre of the sternal plate of the segment is a small subtriangular projection, 

 truncate at the extremity ; the epipodite is longer, more pointed at the end, and bears 

 numerous finely -plumose seta?. 



The third, fourth, and ffth jilcojwda nrt' n\\ similar in form, but each a little larger than 

 the preceding one. PL 11. fig. 1 j^Z/j.'* c3' shows the third pleopod of a male specimen, 

 but will serve almost equally well for that of a female ; from the centre of the sternal 

 plate of the segment arises an oval projection, which is produced distally to a fine point ; 

 there is no trace of the ejiipodite, but on the inner side the protopodite is pi'oduced into 

 a triangular acutely -pointed process the margins of which bear several jdumose setae ; 

 the exopodite is much larger than the endopodite, and is distinctly opercular in structure 

 and has the margins regularly fringed with long plumose hairs ; the fourth and fifth 

 pleopods are similar, but as we proceed posteriorly the endopodites, being less covered 

 by succeeding appendages, become more strongly chitinized and more abundantly su2>plied 

 with stellate pigment cells, the fifth one naturally most so, as it is completely exposed. 



In the male the first and second pleopoda are specially modified for the purjjosc of 

 coptilation. In the first pair the pleopod itself is not very different from that of the 

 female, though the exopodite is rather larger and the endopodite is more pointed at the 

 apex, but it is closely associated with the external male organ, which no douht spriu"'s 

 from the last segment of the mesosome but is adherent to the pi"Otoj)odite of the pleopod 

 and in dissection always comes away with it ; it forms a long, narrow process, slightlv 

 narrowed and curved outwards at the end ; this is grooved throughout its whole len"th 

 on the posterior side, aud during life is closely ])re'ised against the anterior side of the 

 long process formed by the endopodite of the second pleojjod, and with it forms a tube 

 for the passage of the semen. 



In the second pleopod of the male the protopodite and the exopodite present little 

 modification, but the whole of the endopodite is specially modified ; it forms a 2-jointed 

 penial appendage, strongly chitinized throughout, much more so than the male oi'gan 

 proper already described ; the first joint is short, lies transversely, and is moved by 



