On some West-Australian Entomostraca. 33 
behind. Male specimens may, moreover, be at once recog- 
nized by the somewhat darker brown colour of the shell, 
and by the spermatic vessels shining more or less distinctly 
through the valves. As usual, the greater number of these 
vessels is accumulated in the posterior part of each valve, 
there forming a close, winding coil, which however in the 
present form exhibits this peculiarity, that its end is bent 
forward for some distance along the ventral part of the 
shell (see fig. 8). 
Biological Observations. 
Of this pretty species some few specimens, males and 
females, developed in 2 of my aquaria, and were watched 
for some time. They did not, however, multiply to any 
great extent, and before the end of the summer they had 
wholly disappeared. A limited number of specimens, how- 
ever, were previously secured and preserved for closer 
examination. In habits it agrees with the other species of 
the genus Cypris, being rather agile and admirably well 
adapted for swimming, though more generally it kept 
near the bottom of the aquarium. Males and females 
occurred in about equal numbers, and copulation was very 
often seen to take place, showing the species to be pro- 
nouncedly gamogenetic in character. 
3 — Archiv for Math. og Naturv. B. XIX. No. 1. 
Trykt den 19de November 1896. 
