12 G. O. Sars. 
injured the intestine, without the animal having been able 
to rid itself of it. The accompanying drawing was immedi- 
ately executed, and subsequently the individual was care- 
fully preserved, so as to retain its form, and partly also its 
colour, quite unaltered. 
Trib. Concostraca. Fam. Limnadiidæ. 
Gen. Estheria, Rippel. 
2. Estheria elliptica, G. O. Sars, n. sp. 
(Pl. 2). 
Specific Characters.— Y Shell, seen laterally, of a 
rather regularly elliptical form, anything but equilateral, the 
umbones being placed far in front, dorsal margin behind 
the umbones nearly straight, and not angular behind, free 
edges of valves evenly curved throughout, both extremities 
being rounded and nearly equal, though the anterior one 
appears a little more obtuse than the posterior:—seen from 
above, rather tumid, greatest width in front of the middle, 
posterior extremity more pointed than the anterior. Valves 
of rather firm consistency, with 14 very strongly marked 
and elevated, ridge-like concentric lines of growth, each 
provided in their posterior part with short and stout bristles, 
surface between the lines finely and irregularly reticulate, 
marginal area rather broad, and furnishea with numerous 
densely crowded concentric striæ, which are not at all raised. 
Upper surface of head bent at nearly a right angle close to 
the cervical impression, rostrum somewhat blunted at the tip. 
Number of legs 22—23 pairs. Tail of usual shape, with a 
