OBUB1 iHfi 



The body is formed of .seven transverse plates, diMinctK >cparat , 

 with curving end*, as snlliciently exposed by inspection from al 

 besides which an- the first segment, with the eyes and tin- antenna-, ami 

 the last of dim-rent formation from any (if tin- rot, much larger, and 

 hearing the st\l,-. Numerous short bristles invest the margin and many 

 parts of tin- body. 



The whole osjxjct of the creature is very peculiar, and very different 

 from any other in these volumes, though much correspondence may be 

 traced between the number, proportion, and distribution of the part* 

 anionir the whole. This animal feeds upon vegetable matter exclusiveK 

 and. unless the next, it is the only one of the crustacean race with which 

 1 am uciMiainted that does so. The leaves of the beech in decay ure pie 



!. and in such parts of the pond as these are most abundant there 

 the Aseltiut is most numerous. The animal does not swim, it runs freeh 

 and expeditionsly over the decaying leaves, but the smoothness of gloss 

 is BO adverse to the structure of its limbs that it cannot ascend a cydindei 

 without the assistance of some other substance. 



The breeding season extends through several months of the year. 

 The ovarium, in common with that of the other subjects of this section. 

 spreads over the lower part of the thorax and abdomen, consisting of 

 about forty ova, contained perhaps in a sac, or confined by a delicate 

 integument. 



That of a specimen, being white, was far advanced on March 20th. 

 When mature it is yellowish. Many of the young, very minute, and 

 almost white, which had been recently hatched, were running about the 

 vessel, over and under the leaves, on the 22d of May. They hud sen- 

 sibly grown on July 10th, and were then darker than previously. The 

 young animal is about half a line long, and transparent under the micro 

 scope. On July 1 "ith I endeavoured to secure a specimen ascending the 

 side of the vessel, which bore a quantity of spawn on the breast and ab- 

 domen, it escaped, however, to retreat among the refuse Mow ; but. by 

 means of a long glass tube, it was caught next moniiiu 



This animal, being prolific, was well adapted lor elucidating - 

 investigation regarding the ova. Two watch glasses, of unequal 



