62 THE VOYAGE OF H.M.S. CHALLENGER. 



Tlie Trochanter is large ; viewed from the inner side it is subtriangular, and attached 

 to the coxa by a small narrow neck at the anterior lower angle ; viewed from the outer 

 side it is subrhomboidal, with the femur inserted on the upper anterior side. 



The Femur (PI. II. fig. 4 t f-l-, 4 ? f.l., 6 f.l.) is moderately stout, and varies 

 somewhat in shape in difterent species and sexes. 



The Tibia (PL II. fig. 4 $ f.l, 4 ? //., 6/./.) is nearly as long as the femur, and 

 slightly incrassate from base to apex. Above it is crossed near the apex by a furrow 

 rimning obliquely towards the base from the hind to the front margin. The hind margin 

 itself is prolonged into a short nearly straight process which extends a little beyond the 

 apex. 



The Tarsus (PL II. fig. 4 $ f.l, 4 ? f.l, 6 f.l) is attached to the anterior part of 

 the apex of the tibia, and is two-jointed, with the first joint very small. The second 

 joint is fusiform, and cleft and clawed beyond the middle, the claws being furnished with 

 the ribbon-like process already described in Halohates. 



The Middle Legs. 



These limbs are inserted at the lower posterior angles of the thorax. 



The Acetahulum is large and cylindrical, with the opening slightly oblique and circular. 

 The middle line below has a long longitudinal suture or slit. 



The Coxa is ring-like, and much broader than long. 



The Trochanter has a ball-like base lying in the hollowed apex of the coxa ; 

 viewed from the inside it is lanceolate, attached by a slightly curved neck to the ball-like 

 base. 



The Femur is inserted on the under side of the trochanter, and gradually narrows 

 from the base to about the middle, being very slightly incrassate at the apex. 



Tlie Tibia gradually narrows from the base to before the middle, and has somewhat 

 longer hairs on the inner side, but is not furnished with a long fringe as in Halohates. 



The Tarsus (PL II. fig. 5, m.t.) is two-jointed. The first joint is rather thicker at 

 the base, where also it has longer hairs (but not a long fringe) on the inner side. The 

 second joint is cleft and clawed near the tip, and furnished on the outer side with one or 

 two long hairs, as in Halobates. 



TJie Hind Legs. 



These are inserted above the middle legs at the upper posterior angles of the thorax. 



The Acetahulum is large and cylindrical. Each slightly approaches the other pos- 

 teriorly, and the opening is slightly oblic[ue and circular. Viewed from the side, the 

 acetabulum shows an impression on the under side for about half of its length posteriorly, 

 in which impression the middle coxa lies. Between the hind and middle acetabula is a 



