ALONA. 133 



appears free from cilia. The lower margin is obtuse, and 

 the whole shell is very closely reticulated. 



Beak prominent and long, projecting upwards, rather 

 blunt. Eye large for size of animal, areolar. 



Inferior antennae or rami rather slender ; anterior 

 branch provided with four setae, one short from second, 

 and three long and stout, from last articulation ; posterior 

 branch has three from last joint only. 



Abdomen rather tapering towards the extremity, and 

 serrated on inferior margin. 



Intestine convoluted, but it is not easily seen from 

 reticulated surface of shell. One ovum. 



Hob. Pond near Southall, Middlesex, July 1841 ; 

 September 1849. 



3. ALONA OVATA. Tab. XVI, fig. 2. 



Ovately globose ; transparent ; shell striated ; striae 

 waved longitudinally. 



Superior antennae short. Beak of carapace or shell 

 rather short and blunt. 



Anterior edge of shell densely ciliated. Eye areolar, 

 anterior black spot large. 



The head is erect, as in A. quadrangularis. 



Intestine convoluted. 



Tail hollowed out a little, about the centre of its in- 

 ferior edge, then bulges out, and is armed with short 

 spines, and finally terminates in two short, curved claws. 



In size it is rather larger than the A. quadrangular is. 



Pond on Blackheath, April 1848. 







