136 G. 0. SARS. CRUSTACEA. [norw. pol. exp. 



all being gently curved below. As these limbs are generally extended straight 

 behind, the ends of the apical setae are most frequently seen projecting from 

 the hind edges of the shell (see PI. XXXV, fig. 3). 



On the left side of the abdominal part of the body, at some distance 

 from the caudal plates, a rather large, oblong oval piece occurs, projecting 

 freely below, and somewhat anteriorly (see PI. XXXV, fig. 3, PI, XXXVI, 

 figs. 10, 11). This is the single copulative organ, containing the outer part 

 of the seminal duct. 



The inner organs cannot, of course, be very closely examined, except 

 in fresh specimens. However, by a suitable preparation of the extracted 

 body, it can be made sufficiently pellucid to show some of these organs 

 rather distinctly (see PI. XXXV, figs., 1, 3). The intestine especially is 

 easy to observe, forming a very capacious sac-like cavity, located in the 

 abdominal part of the body, and generally filled with contents of an 

 opaque, dark appearance. It debouches by a short rectum between the 

 caudal lamellae, and to its anterior extremity leads a highly muscular 

 CESophagus, ascending obliquely from the oral aperture. By dissection, 

 this part of the intestinal tract is not infrequently obtained in connec- 

 tion with the chitinous skeleton surrounding the mouth, and can thus 

 be subjected to a closer examination (see PI. XXXVI, fig. 1). It is 

 coarsely annulated throughout, and is attached to the walls of the body 

 by numerous short muscles. Its distal extremity expands into a large 

 hollow disc, which projects freely within the lumen of the intestinal cavity. 

 The contents of the latter consist of a compact infiltrated mass, in which I 

 have failed to detect any recognizable remains, either of algae or of animals. 

 Probably the food is so finely triturated by the mandibles, that no part of it 

 is left unaltered. 



In the female, the ovaries also, with their numerous egg-follicles, may 

 be pretty clearly traced, owing to their opaque white colour, contrasting 

 strongly with the dark contents of the intestine (see PI. XXXV, fig. 1). 



The young do not seem to undergo any metamorphosis, all the limbs 

 being present, even in specimens which have evidently just escaped from 

 the ova. The shell of the young animal, however, is rather different 

 in shape from that of the adult animal, being far less elongated, and in 



