Fresh-water Entomostraca of South America. 75 



Biological Observations. — It was by a mere 

 chance that I became aware of the presence of this peculiar 

 form in one of my aquaria, which I had previously examined 

 very closely in search of other Lynceidæ. The peculiar 

 habits of the animal had, however, prevented me from catch- 

 ing sight of the present interesting form, and it was only 

 when I once happened to look at the aquarium from above, 

 that I detected it. Contrary to other Lynceids, this form 

 kept constantly at the very surface of the water, swimming 

 about there in a very peculiar jumping manner, wholly un- 

 like that seen in any other known Lynceid. To the naked 

 eye, it looked like a little black atom darting about in a 

 most wonderful manner; nor was it easy to catch the little 

 animal, which escaped with great dexterity, when any object 

 approached it. I only succeeded in securing some few fe- 

 male specimens. My search for it in other aquaria was quite 

 fruitless. 



Occurrence. — The aquarium in which this form 

 occurred, was rather a small one, in which there was a very 

 luxurious growth of aquatic plants. It had been prepared 

 with mud from Itatiba. 



Distribution. — The specimens examined by Mr. 

 Daday, were taken from 2 different places in Ceylon. 



Gen. Dunhevedia, King. 



Syn: Crepidocercus, Birge. 

 Remarks. — This genns was established by King as 

 early as the year 1853, to comprise 2 Australian species, 

 D. crassa and D. podagra. One of these species (D. crassa) 

 I succeeded in raising from dried Australian mud, and it 

 was described and figured in detail in my paper «On some 



