74 



middle, with a slight angular bend in the ocular region, and sloping rather 

 abruptly behind, ventral margin distinctly sinuated, anterior extremity rounded, 

 posterior obliquely deflexed, with the infero-posteal corner somewhat prominent, 

 though evenly rounded off at the end; seen dorsally, narrow oblong in outline 

 with the greatest width not nearly attaining half the length. Surface of valv 

 smooth and shining, though exibiting a number of well marked scattered pi 

 and clothed at each extremity with short and delicate hairs. Posterior le 

 conspicuously more slender than in the type species, and having the penultima 

 joint distinctly subdivided in the middle. Caudal rami rather slender an 

 attenuated and slightly curved, apical claws comparatively shorter than i 

 C. Candida, the distal one not nearly attaining half the length of the ramu 

 dorsal seta rather small and more approximate to the end. Genital lobes 

 rather inferior size, but distinctly angulated behind. 



Male somewhat larger than female, and differing from it conspicuously 

 in the shape of the shell, the posterior part of which is broadly rounded off 

 and peculiarly expanded below, ventral sinus of the shell being moreover 

 considerably deeper. Prehensile palps of maxillipeds comparatively shorter and 

 stouter than in the preceding species, with the dactylar part less produced. 

 Caudal rami perfectly straight and still more narrowly exerted than in female. 

 Copulative appendages resembling in structure those in C. Candida, though 

 having the upturned lappet comparatively larger and subcordiform in shape 



Shell in both sexes of the usual pure white colour, and somewhat le 

 opaque in male than in female. 



Length of female amounting to 1.30 mm. of male to 1.40 mm. 



Remarks. This form was first described as a distinct species by the prese 

 author in the year 1887 from specimens taken in the Garda lake, upper Ital 

 It was however not recognised by subsequent authors, Brady & Norman havin 

 confounded it with C. Candida, and Vavra with C. fabceformis. It is howeve 

 evidently specifically distinct from either of these species, as admitted by a 

 recent authors. The form recorded by Lilljeborg as early as the year 185 

 under the name of C. Candida is quite certainly not that species, but is mor 

 properly referable to the form here under question. 



Occurrence. The present species, it is true, has not yet been found withi 

 the limits of Norway. As it however occurs in the immediately adjacent tracl 

 of Sweden, it is very likely to believe that, on a closer investigation, it wi 

 be met with in one or other place of the south eastern part of our country 

 The figures here given are drawn from specimens raised in my aquaria ut 

 dried mud from Algeria. 



