156 



Flagellum of posterior antennae well developed. Vibratory plate of mandibular 

 palp rounded in shape and edged with 5 setae. Legs slender and considerably 

 increasing in length behind. Posterior part of body flattened, spoon-shaped 

 and terminating in an upturned spiniform projection. 



Male. Shell comparatively more elongate and more evenly compressed 

 than in female, being distinctly higher in front than behind, with the posterior 

 extremity much less tumid and, seen laterally, obliquely rounded. Right 1st leg 

 distinctly prehensile, with the terminal joint considerably thickened and evenly 

 curved, seta of 1st joint transformed to a strong curved spine with a small 

 bristle outside, apical claw very powerful. Right 2nd leg with the terminal 

 part 'scarcely longer than the basal one, and of very feeble consistency, without 

 any armature whatever. Right 3rd leg with a dense brush of hairs on the 

 1st joint of the terminal part. Copulative appendages with the basal part very 

 large and tumid, rounded oval in shape, and sending of inside, at the junction 

 with the terminal part, a highly chitinised rodlike process pointing obliquely 

 forwards, terminal part not sharply defined from the basal one, and of some- 

 what triangular shape, being produced in front to an acuminate lappet, posterior 

 extremity irregularly rounded. 



Colour of shell in both sexes dark brownish; limbs bright yellow. 



Length of adult female 1.03 mm., of male 1.10 mm. 



Remarks. The above-described form has generally been considered as 

 only a variety of Cyprideis torosa Jones. In this view I am not prepared to 

 assent. The form originally described by Jones differs conspicuously by the 

 strongly marked lateral protuberances of the shell, which indeed have occasioned 

 the specific name given to it by its detector. Moreower the shape of the 

 shell is rather different, as seen from the figures given by Brady in his 

 Monograph of post-tertiary Entomostraca. The specific name littoralis was 

 assigned to the present form by Brady as early as the year 1868, and musr 

 of course be retained for this species. 



Occurrence. The only place where I have hitherto met with this form, 

 is in a brackish lake, Engervand, at Sandviken, West of Christiania. It occurrec 

 here rather abundantly at the borders of the lake together with Cypridopsh 

 aculeata. 



Distribution. Baltic, British Isles, Holland, France, See of Azow, Central 

 Asia, North Africa. 



Fossil. Sweden, Scotland. 



