60 Gr. O. Sars. 



and nearly equal; — seen from above broadly ovate, greatest 

 width not exceeding the height, anterior extremity obtusely 

 pointed, posterior evenly rounded. Valves rather unequal, 

 the right one overlapping the left considerably in the middle 

 of the dorsal face, as also anteriorly. Surface of shell 

 smooth, or very slightly granular, moderately hairy, with a 

 narrow, transversely-striated, marginal area just within the 

 anterior edge of each valves. Colour yellowish, variegated 

 with dark green, partly anastomosing patches. Length of 

 shell 0,92 mm. 



Remarks. — This is undoubtedly the true C- minna of 

 King, and the form described by Brady also belongs quite 

 certainly to the very same species. On the other hand, the 

 form described by the present author under this name from 

 New Zealand is specifically distinct, as will be shown farther 

 on. The present species may be easily recognized from any 

 of the other known forms by the extraordinary height of the 

 shell, which gives it, in a lateral view, nearly a trigonal shape. 



Description of the female. 



The length of the shell in fully adult specimens mea- 

 sures 0,92 mm., and accordingly somewhat exceeds that of 

 the said New Zealand form 



Seen from the side (fig. 5 a), the shell exhibits a some- 

 what unusual form, being exceedingly high and almost tri- 

 gonal in outline, with the greatest height not very inferior 

 to the length, and occurring in the middle. Both extremi- 

 ties appear somewhat obliquely rounded, and nearly equal. 

 The dorsal margin is very boldly arched, exhibiting an 

 almost angular bend in the middle, and from thence sloping 

 rather steeply both anteriorly aud posteriorly. The ventral 

 margin is but very slightly sinuated in the middle. 



