Fresh-Water Entomostraca from China and Sumatra. 15 



16. Alona costata, G. O. Sars. 

 Occurrence. — Found in some of my aquaria prepared 



with mud from China. 



Distribution. — Europe, Central Asia. 



17. Aloua guttata, G. O. Sars. 

 Occurrence. — Specimens of both the tuberculated and 



smooth varieties occurred not unfrequently in the aquaria 

 prepared with mud from Sumatra. 



Distribution. — Europe, Central Asia, Algeria, Brazil. 



18. Aloua acuticostata, G. O. Sars, n. sp. 



(Pl. I, figs. 5, 5 a — c). 



Specific Characters. — Female. Carapace, seen later- 

 ally, oval quadrangular in form, greatest height in the 

 middle, dorsal margin forming quite an even curve as far 

 as the tip of the rostrum and terminating behind in an 

 obtuse corner, ventral nearly straight, or very slightly pro- 

 minent in front of the middle, hind edges somewhat curved 

 below. Head rather procumbent, rostral projection of mo- 

 derate size. Surface of shell very coarsely striated longi- 

 tudinally, striæ rather prominent, ridge-like, about 15 on 

 each side, lower edges of valves minutely setiferous, and 

 each exhibiting at the posterior corner a small denticle. 

 Ocellus smaller than the eye, and somewhat nearer to it 

 than to the tip of the rostrum. Lip-plate of the usual shape. 

 Caudal part comparatively small, not expanded distally, 

 supra-anal angle rather slight and occurring somewhat above 

 the middle, lower corner obtusely rounded, denticles of the 

 marginal rows rather small, about 10 on each side, those 

 of the lateral rows extremely delicate, terminal claws rather 

 strong, each with an unusually long denticle at the base. 



