8 G. 0. Sårs. 



the fornix of the cephalic shield joins the carapace. Seen 

 from above or beneath (fig, 2), the carapace appears rather 

 tumid, with the greatest width occurring in the middle, and 

 being somewhat less than the height. The valvular part of the 

 carapace does not admit of being completely closed, and ex- 

 hibits below, in the middle, a rather broad, open space, within 

 which the legs with their strong claw-like spines are visible 

 (see fig. 2). Behind, the edges of the valves approach one another 

 somewhat more closely, allowing the caudal part, however, to 

 be freely moved between them. The free edges of the valves 

 are clothed along- their whole inferior and posterior parts 

 with a double row of ciliated setæ, those of the one row 

 extending more or less outwards, those of the other in- 

 wards. At the inf'ero-posteal corners, the setæ are parti- 

 cularly strong and elongated, some of them assuming a spini- 

 form character (see PI. II, fig. 2). 



The shell-glands are visible in the anterior part of the 

 valves (see PI. I, fig. 1, PI. II, fig. 1), each fiarming a simple 

 anteriorly-curving coil of apparently 3 channels, and extend- 

 ing downwards from about the point Avhere the free part of 

 the valves takes its origin. 



The front part of the body, or the cephalic shield (see 

 PI. II, fig. 1), as above stated, is very sharply marked ofi: 

 from the carapace, a deep dorsal depression occurring between 

 the two. It is about half as long as the carapace, and some- 

 what procumbent, with the dorsal margin obliquely curved 

 and forming in front an obtusely rounded protuberance, in- 

 side which the eye is situated. Below, it projects into an 

 obtuse rostrum, carrying on the tip the antennulæ. The 

 ventral part of the head is much compressed, with the edge 

 nearly straight and perfectly smooth, joining the labrum just 

 at the front corners of the valves. The fornix is not very 



