68 On Australian Entomostracans. 



a kind of tooth. Doubtless the object of this is to assist in 

 clasping in coitu. The legs are also modified to assist in 

 the same operation, carrying stout hooks instead of the 

 long and sharp points found in Cypris. 



In the female the rami and legs are exactly similar to 

 those of Gypris, except that the last joint of the former is 

 very long, being nearly half as long as the preceding. 



It is terminated by only two stout setse, fig. 9. 



The mandibulary palpus is very stout ; it is similar in its 

 general form to that of Cypris. 



The first foot jaw has its extremity opposite to the branchial 

 plate divided into three fingers, instead of four, as in many 

 species of Cypris ; the fourth, which is generally jointed in 

 the latter genus, being here wholly wanting. 



The generative organs correspond almost entirely with 

 those of Cypris carinata. 



Hahit. — This very common but interesting species lives 

 almost wholly near the surface of the water ; — its boat-like 

 plate enabling it to walk along the under surface, while its 

 eyes, directed downwards, give immediate notice of the 

 approach of an enemy. When alarmed, it immediately 

 sinks to a little distance, and then swims off", only coming 

 to the surface when all becomes tranquil. The hand passed 

 over the water near the surface, so as to intercept the light, 

 or the surface being disturbed by the slightest breath, in- 

 stantly alarms them. They are the most active when the 

 sun is shining ; and often a whole troop of them may be 

 noticed swimming round and round, and in and out, with a 

 most lively and graceful motion, about an inch beneath the 

 surface, in some spots more favoured than others by the 

 warmth of the sun. I have never looked at them whilst thus 

 engaged without receiving the impression, that, under such 

 circumstances, they were perfectly happy. I have named 



