OEUSTACEA OF NEW ZEALAND. 237 



four larger tufts ; along the extremity is a row of about seven auditory seta;. The 

 flagellum is rather longer than the peduncle, and is stout, especially toward the base, 

 where each joint is much broader than long. It bears two rows of calceoli, arranged in 

 the same way as in the upper antenna; the calceoli decrease in size towards the end of 

 the flagellum, and cease entirely at about the seventh joint from the end. In addition 

 to the calceoli each joint bears a few simple setae at the extremity. 



The general appearance of the calceoli is shown in fig. 3. These organs have been 

 fully investigated by Blanc, as I learn from the abstract given by Stebbing. The 

 general arrangement of the calceoli in the present species appears to resemble closely 

 that in Eusiroides ccesaris as described and figured by Stel)bing [108, p. 970]. When 

 seen in profile, the outline of the calceolus is very dififerent from that shown in fio-. 3, 

 and is more like that shown by Stebbing in his figure of the calceoli of Tryphosa 

 antennipotc7is [108, pi. vi. fig. a. s. with enlargement]. In that species, too, the 

 calceoli on both antennae are arranged in the same way as in the present species — 

 " in both pairs so j^laced that, while the calceoli of alternate joints are seen full face, 

 those of the other alternate joints will be seen in profile " [108, p. 018]. 



The njyjje)' llj) (fig. 5) is rather large, oval in outline, widening distally ; the end is 

 regularly rounded at the corners and nearly straight in the centre, and bears many short 

 converging setae. 



2Iandibles (figs. 6, 7, 8). The left mandible is shown in fig. 6, and difibrs consider- 

 ably from the right in the details of the cutting-edges. The palp, which is the same in 

 both mandibles, is large and rather broad. Its first joint is very short, not much longer 

 than broad; it bears no seta;. The second joint is the largest, being rather more than 

 three times as long as the first ; it expands slightly towards the distal end, and bears at 

 the extremity on the inner margin, which is there convex, a row of six or seven fairly 

 long setae. The third joint is about three-fourths as long as the second ; it is broadest 

 near the base, narrows considerably toward the end, and is much ciu'ved, so that the 

 extremity is almost at right angles to the plane in which the base of the joint lies (the 

 double curving is not well shown in the figure). Along its concave margin it is thickly 

 fringed with a dense row of short seta; ; three longer ones are situated at the extremity. 

 The surface on the concave side appears striated, the appearance being probably due to 

 rows of very minute setae. 



The molar tubercle is strong ; it has the extremity oblique, and covered, as usual, with 

 rows of short spines. The sides of the tubercle bear numerous fine setae, and in 

 connection with it is a long filament or seta, as described by Humbert in Nlphargus 

 puteanus, by Sars in Gammarus neglectus, and by other authors. 



The outer cutting-edge of the left mandible (fig. 7) consists of about six sharp 

 teeth of varying shape, as shown in the figure ; the inner or secondary edge is somewhat 

 similar, but contains only four main teeth. Both edges are very concave on the inside, 

 and were a good deal compressed in the slide from which fig. 7 was drawn ; between 

 the inner edge and the molar tubercle are five or six stout bristles. 



The right mandible difiers principally from the left in the two cutting-edges. The 

 outer edge is similar to that of the left, but appears to consist of five main teeth only, 



31* 



