164 ON THE ANATOMY OF ENTOMOSTRACA, 



size. Before the end of Octobci' all had disappeared from the 

 swamp ; but some remained in my aquarium alive and well 

 until the end of November. 1 have also found the species at 

 Paramatta. 



Their manner of swimming very much resembles that 

 of the Lynceidce, a quick succession of short jerks. When, 

 copulation takes place, the male seizes the female between its 

 beak and the ventral edges of its carapace, and swims about in a 

 most excited manner — the shell of the female being at this time 

 wholly closed. After a time she begins to open her shell, when 

 the clasping legs of her consort seize the edges. 



Daphnia Carinata. 



The DaphniadcB are well represented in the neighbourhood 

 of Sydney by at least seven species belonging to the genera 

 Daphnia Macrothrix and Moina. Of these, the species named 

 above is by far the largest and one of the most common. It is 

 subject to very great variations, which appear to be constant in 

 particular localities. It is easily bred, and, from its size, easily 

 observed in an Aquarium. 



Plate XII. contains an accm^ate representation of all the 

 branchial legs of the female. They much resemble the corres- 

 ponding parts of D. Schcefferi as figured in Baird's " British 

 Entomostraca.''^ There is, however, one important difference — 

 or rather addition — in my figures, viz., that in all these the 

 hairless lobe appears corresponding to that already described in 

 the anatomy of Limnetis. In Mr. Baird's plate this lobe does 

 not appear in the 1", 2"*, and 3"* pair of legs ; the upper 

 portion of it is drawn in the figure given of the 4*, and the 

 whole of it in that of the 5*. 



In the Phijllopoda, it is remarkable how through all the 

 branchial legs the same lobes may be traced, so that the last 

 of 11, 17, or 27 pairs exhibits a very close correspondence with 

 the 1"** and 2"'*. The normal number of lobes may be traced 

 even in the clasping legs of the male. But in Daphnia this 

 rule does not obtain. With the exception of the 8"^ and 4"' the 

 dissimilaritij is as remarkable. Even in the number of lobes 

 as well as in their arrangement, there is a considerable difference. 



