386 Transactions of the Society. 



central projection. Inside the ring are the labia ; the two ordinary 

 (lateral) labia are very widely separated posteriorly, and between 

 them is an unpaired, posterior, almost triangular labium opening 

 downward and backward. The anus is far back, much smaller 

 than the vulva, and is a long-shaped ellipse ; there are a pair of 

 short spines behind it. 



Male (figs. 3 and 4). 



It will be seen by the measurements that this sex is considerably 

 smaller than the female, but not more so than is usual in the 

 genus. 



Cephalothorax. This does not differ much from that of the 

 female, except in being somewhat shorter and broader in propor- 

 tion — a remark which will also apply to the mandibles. There 

 are, however, necessarily some differences in the epimera apodemata 

 and sternal sclerites as follows. I'he band behind the labium and 

 the sternum are nearly similar, the latter being rather longer and 

 its posterior bifurcation forms a small close arch instead of the 

 wide open arch formed by the corresponding parts in the female. 

 The epimera from behind the first, second, and third legs, with the 

 corresponding apodemata, join this arch. There are short epimera 

 from behind the fourth leg not joined to any other sclerite. The 

 intromittent organ is placed in the median line between the coxae 

 of the fourth pair of legs ; it is large, somewhat conical, and points 

 forward; its point, when at rest, lies within the above-named 

 sternal arch. It is divided -proximally into two diverging blades, 

 and is protected on each side by a small, curved, chitinous band. 



Legs. It is here that the main difference from the female 

 will be found ; and, moreover, these organs are probably the most 

 singular and interesting part of the creature, except its life-history ; 

 the first two pairs are very remarkable. Instead of the compara- 

 tively thin legs of the female, those of the male are extremely 

 thick and heavy ; the coxae, tibiae, and third joints being thicker 

 than they are long (figs. 13 and 14). The most remarkable feature, 

 however, consists in certain projections from the under side of the 

 two front pairs of legs. From the median line of the under side of 

 the tibia of each of these legs there stands out a projection bearing 

 a flat, fan-shaped blade of clear colourless chitin edged by seven to 

 nine very deeply cut teeth or spikes, radiating outward. On the 

 under side of the second joint of the second leg are two blades of 

 similar texture ; the proximal round, with a thickened central boss ; 

 the distal curved but longer in shape ; and both these are edged 

 with radiating spikes similar to those on the projection from the 

 tibia. The tarsi of the two front pairs of legs have broad curved 

 blades, both above and below, in the median line ; and there is one 



