specimens of the same species raised from another lot of 

 mud from the same locality. One of the specimens was still 

 quite young, whereas the other, from which the figures here 

 given were made, had attained its full development. I may add, 

 that of the 2 Chinese species, raised last summer, male speci- 

 mens seemed to be nearly as numerous as females, whence the 

 propagation in this genus must on the whole be named a sexual 

 one, though at times also a partenogenesis might take place. 



As to the habits of this species, it is a true bottom form 

 and, as is also the case with the other species of the genus, 

 may generally be found more or less deeply immerged in 

 the loose bottom deposit, so as to be rather difficult to detect. 

 Very often, moreover, the shell is covered with a thick crust of 

 dirt that causes it easily to be overlooked. It is however by 

 no means devoid of swimming power, as may be a priori in- 

 ferred from the greatly developed natatory setae on the antennse. 

 In fact the animal is at times seen to leave the bottom, swim- 

 ming rapidly through the water; but this movement, being 

 apparently rather laborious, never continues for any length 

 of time and is soon stopped, when the shell, by its relative 

 great weight, rapidly sinks back to the bottom. 



Occurrence. — The only locality as yet ascertained for 

 this species is the Gracemere Lagoon, all the specimens being 

 raised from mud collected at that place. 



Gen. 5. Cypridopsis, Brady. 

 Generic Characters. — Shell very tumid, more or less glo- 

 bular in form, dorsal margin boldly arched, ventral nearly 

 straight. Valves subequal, rather thin, hairy, inner duplicatures 

 narrow. Eye unusually broad, transverse. Upper antennse 

 comparatively short but having very long natatory sets; lo* er 

 antennae rather powerful, with greatly elongated apical claws, 

 and the natatory setae reaching beyond their tips. Labrufl 1 



