1818. 



or THE GENUS NiESA. 483 



ciiUued and with a profound sinus at tip; first caudal 

 segment conspicuous. 



Inhabits Eggharbour. 



Cabinet of the Academy. 



Body oblong-oval, semicyUndrical, a little attenuated 

 before, segments equal, first one longer, nearly equal to 

 the head; first segment of the tail equal to tho^e of the 

 body, with three distant tubercles above, terminal seg^ 

 ment as long as the four preceding ones conjunctly, de- 

 pressed near the tip, and marked by a deep sinus, within 

 which are two or four small teeth, and above its base a 

 larger vertical one, base of the, segment with three dis- 

 tant tubercles, the lateral ones double; lateral processes 

 spiniform, a little incurved, surpassing the tip of the seg- 

 ment; eyes longitudinally oval, convex, prominent; ante- 

 nor feet simple, resembling the others; colour fuscous. 



Length rather more than one fourth of an inch. 



Found on the sea beach, in small pools of water left 

 by the recess of the tide. 



2. ^, depressa*, i?ofi^z^ broad, depressed, linear; ^r^f 

 caudal segment concealed, second attenuated; anterior 

 feet monodactyle. 



Inhabits Eggharbour. 



Cabinet of the Academy. 



Body broad, depressed, punctured, sides parailel; 

 segments subequal, anterior ones rather shorter; Jirst 

 segment of the tail not visible, second equal, as long as 

 the three preceding visible ones, attenuated to an obtuse 

 point, which is carinated above and attained by the late- 

 ral, spiniform, acute processes, beneath concave, effuse at 

 tip, eyes apparently lunated, but really rounded, with 



