TERKESTKIAL ISOrODA OF XEAV ZEALAND. 125 



tlio seventh pair of logs as "much smaller than tlie others, weak," it is nevertheless true 

 that ill tliis species the development of these legs appears to he delayed longer than is 

 usually tlie case. In specimens of from 4 to 't nun. in length, which are running 

 actively on tlie heacli and not otherwise immature, the seventh segment of the mesosomc 

 is small and tlie seventh ])air of legs repi-esented either hy a small hud or hy a weak, 

 non-chitinised appendage, m ith the joints only faintly indicated and surface free from 

 seta?; in specimens a little larger ((i mm.) the seventh segment is more developed, hut 

 still smaller than the sixth, and the legs are of the usual shape hut smaller than the 

 sixth and less ahundantly supplied Avith setae. In specimens of 9 mm. in length I found 

 the seventh segment and appendages fully developed ; the male organs were also present, 

 and the specimens apparently fully adult. 



Most of the more important points in the appendages of this species have heen 

 referred to in the discussion of the genus already given. I gi\e here a i'cw additional 

 notes. 



The maudihles are of the type usual in the family. The outer cutting-edge in the 

 right contains three or four stout teeth, brown in colour and higlily chitinised ; the inner 

 cutting-edge is more transparent, slender, and ends in two large teeth and one or two 

 smaller ones ; it is followed by a membranous lappet, the sides and margin of which 

 are densely setose; between this and the dense tuft of stilF plumose bristles is a single 

 large plumose seta. The left mandible is very similar, but the inner cutting-edge is 

 much larger and stouter, and ends in three large teeth which are brown in colour and 

 as strongly chitinised as those of the outer cutting-edge, and there are two plumose 

 setre between the membranous lappjet and tlie tuft of seta? representing the molar 

 tubercle. 



Tiie first maxilla is of the usual form; in the second the extei'nal lobe at the end is 

 very small, and the outer margin shows a proininenc!' near the base like that drawn and 

 described by Sars in Oiiiscus and some allied genera. 



In the maxillipede the exopodite is about half as long as the bases, oblong with the 

 end rounded ; the outer margin of the basos is somewhat expanded, and is fringed with 

 line setfe towards the distal end ; the masticatory lobe is about half as long as the 

 terminal j^ortion of the nraxillijiede, and lias the end obliquely truncate and fringed with 

 setae ; the ischium is short, distinctly separated from, adjacent points ; on the outer aspect 

 of both the basos and ischium are three or four short sette near the distal margin ; the 

 four terminal joints are coalesced into a single laniclliforra plate, with four distinct lobes 

 on inner side representing the different joints of which it is composed. 



The legs of the mesosome are sjjiny, the anterior pairs shorter and stouter than the 

 posterior; the dactylus is long, and has its basal jiart thickly covered with short setae, 

 the terminal claw long, narrow and slightly curved, secondary claw very narrow, almost 

 like an ordinary seta. There is no special " dactylar seta." 



In the male the first pleopod is remarkable in having the exopodite very large and 

 operculiform ; it is articulated as usual to the lateral part of the prolopodite, and extends 

 anteriorly and posteriorly into two large rounded lobes, which show branching thiokea- 



19* 



