22 G. 0. Sårs. 



form, with the greatest height shghtly exceeding ^/s of the 

 length, dorsal margin well arched, with the greatest curva- 

 ture about in the middle, and terminating both in front and 

 behind in a distinct angular corner, ventral margin evenly 

 curved, and joining the anterior and posterior edges without 

 any intervening angle, both extremities nearly equal and ob- 

 tusely rounded; seen dorsally, narrow fusiform in outline, 

 greatest width about Vs oî the length, and occurring in. front 

 of the middle, both extremities acuminate. Valves thin and 

 pellucid, each with only 3 lines of growth confined to the 

 peripheral part of the shell, surface perfectly smooth, edges 

 ^\àthout any setæ. Animal. Head, seen laterally, regularly 

 triangular in form, with the ocular protuberance narrowly 

 rounded and not defined by any distinct sinus either above 

 or below, rostral projection almost rectangular, dorsal margin 

 evenly arched, affixing organ not very large. Eyes compara- 

 tively small, sub-confluent, Antennulæ remarkably short, 

 with only 4 lobules anteriorly. Antennæ with the rami sub- 

 equal, each composed of 7 or 8 articulations. Legs of the 

 usual structure, the epipodite being rather large and mem- 

 branous. Caudal piece with 2 very distinct juxtaposed denti- 

 form processes in front of the terminal claws, the latter 

 scarcely longer than the remaining part of the piece and 

 setous along the hind edge, their apical part short and mi- 

 nutely denticulate; caudal plates each produced below to a 

 straight spiniform projection and armed along the posterior, 

 nearly straight edge with 8 or 9 rather uniform denticles, 

 dorsal face, above the caudal setæ with 2 pairs of some- 

 what stronger denticles. Ova globose, surrounding capsule 

 with polygonal depressed areas. Length of shell 6V2 mm. 



Remark s. — This form so strongly resembles the Austra- 

 lian species described by the present author as E. Dahli, 



