Fresh-Water Entomostraca from China and Sumatra. 31 



straight, anterior extremity broadly rounded and angular 

 below, posterior somewhat narrower and blunted at the tip; 

 — seen dorsally, ovate in form, greatest width somewhat 

 exceeding half the length and occurring behind the middle, 

 anterior extremity more attenuated than posterior. Valves 

 perfectly equal, each with a broad hyaline rim in front, 

 buth without any trace of the denticle at the infero-posteal 

 corner present in N. monacha, lower edges abruptly inflexed 

 in front, so as to form together a flattened lozeng-shaped 

 ventral area; surface smooth and shining, with scattered 

 hairs at each extremity. Eye exceedingly large and con- 

 spicuous, consisting of a large distinctly bilobed pigmen- 

 tary mass carrying on each side a highly refractive lens. 

 Caudal rami of moderate size, slightly tapering distally, 

 apical claws very slender and minutely denticulate, the outer 

 one equalling about f of the length of the ramus, seta of 

 dorsal edge well developed, apical one obsolete. 



Colour. — Shell semipellucid, of a whitish colour, with 

 a very dark shadow on each side below the muscular im- 

 pressions, expanding in front to a large patch, behind to 

 a narrow band-like stripe. 



Length of shell 0-59 ™'n, height 0-42 m™, width 032 ™"\ 

 Remarks. — This form differs conspicuously from the 

 European species, N. monacha (Müll.), by the absolute ab- 

 sence of the dentiform projection of the valves at the infero- 

 posteal corner, as also by the extraordinary development 

 of the eye. Nor can it properly be referred to the Ceylon 

 species described by Dr. Daday as N. Entzii, differing, as 

 it does, both in the shape and colour of the shell. It is 

 also much inferior in size to any of the 2 above-mentioned 

 species. 



