44 G. o. SARS. M.-N. Kl. 



the curved spines found, in the latter species, distributed along the dorsal 

 face of the shell. 



Description of the female. 



The length of adult specimens measures about 0,70 mm., and this 

 form, accordingly, about equals, in size, the above-named European species. 



The shell is rather short and stout, and somewhat compressed (comp, 

 fig. 4 a & 4 b), the greatest width not nearly equalling the height. 



Seen laterally (fig. 4 a), it exhibits a rounded triangular form, the 

 greatest height exceeding 2/3 of the length, and occuring in the middle. 

 The dorsal margin is boldly curved, forming, in the middle, an abrupt, 

 almost angular bend, and sloping somewhat more steeply in front than 

 behind. The ventral margin exhibits in the middle a distinct, though not 

 very deep sinus. The anterior extremity is somewhat obliquelv rounded, 

 the posterior one obtusely blunted. 



Seen from above (fig. 4 b), the shell appears rather narrow, and of 

 an oblong ovate form, with the greatest width scarcely exceeding half 

 the length, and occurring somewhat behind the middle. It tapers, ante- 

 riorly, to a sharp point, whereas, posteriorly, it is more obtuse. 



The valves are less unequal than in some of the other species (ex. 

 gr. P. villosa), though, on a closer examination, as in these, the right one 

 is found to be the larger, slightly OA'erlapping the left along the anterior 

 extremity. The inner duplicatures are not particulary large. 



The surface of the shell is distinctly granular, and of a dull appearance, 

 exhibiting a somewhat squamous sculpturing. It is everywhere densely 

 hair}'; but no trace of the curved spines occurring in P. acnlcata among 

 the hairs dorsally, is to be detected. The muscular pits are easily 

 observable in the centre of each valve, and exhibit the usual arran- 

 gement. 



The eye is of moderate size, and located somewhat in front of the 

 middle dorsally. 



The several limbs agree in their structure with those in other species 

 of the genus. 



The candal rami (see fig. 4 c) exhibit the structure characteristic of 

 the genus, and are very different from those in the genus Cvpridopsis. 

 They are extremely small, lamellar, and terminate each in a long seta, 

 having, besides, another much shorter one at some distance from the tip 

 dorsally. 



The colour is a rather uniform and very dark green. In adult 

 females the posterior part of the shell generally exliibits, on each side, a 



