74 G- O. Sars. 



39. Dadaya macrops (Daday). 



(PI. XI, figs. 5, a— b). 



Alona macrops, Daday, Mikroskopische Süss wasserthi ere aus Cey- 

 lon,, p. 38. 



Specific Characters. — Female. Carapace, 

 seen laterally, rounded oval, somewhat approaching a quadran- 

 gular shape, height about equal to the length, dorsal margin 

 evenly arched, ventral a little bulging in front, but other- 

 wise only slightly curved, posterior extremity obtusely trun- 

 cated, upper corner more distinct than lower. Head with 

 the dorsal face conspicuously protuberant in the ocular region, 

 rostral projection rather broad, straight and deflexed. Sur- 

 face of shell distinctly reticulate, anterior part of valves 

 with 8 or 9 curved transverse striæ, partly crossed by less 

 distinct longitudinal ones, lower edges finely ciliated. Eye 

 very large, with numerous crystalline cones ; ocellus fully as 

 large as the eye, but of an irregular oblong quadrangular 

 form. Antennulæ narrow fusiform, their outer half project- 

 ing beyond the tip of the rostrum. Antennæ comparatively 

 short. Lip-plate terminating in a narrow acuminate point. 

 Caudal part rather large, and somewhat widening distally, 

 dorsal edge below the anal orifice forming a perfectly even 

 curve, supra-anal projection rather slight, lower corner obso- 

 lete, marginal denticles well defined, about 16 — 18 in each 

 row, caudal claws comparatively small, each with a well- 

 marked spinule at the base, distal part very finely denticu- 

 late. Colour very dark brown, or almost black. Length of 

 adult female 0.31 mm. 



Remarks. — No doubt as to the identity of the above- 

 characterized form with that recorded by Mr. Daday, can 

 arise, agreeing, as it does, in all essential points very closely 

 with the description and figures given by that author. 



