NOTES ON A NEW SPEf'IES OF CIYMNOPLEA. 



Notes on a New Species of Gyinnoplea from 

 Richinond, Natal, South Africa; Adiaptomus 

 natalensis (gen. et sp. nov.). 



By 

 Arnold W. Cooper, F.R.ITI.S., etc. 



With Plate XII. 



The following notes on a new species of Gyninoplea found 

 by Mr. J. Y. Gibson and myself near Bieliniond in November, 

 1905, may be of interest. During the latter part of 1905 we 

 had been making periodical visits to several pools in a marsh 

 with the view of ascertaining what varieties of aquatic life 

 occur during the cycle of the year. During the months of 

 August, September, and October Diaptoraus or lent alls 

 was plentiful ; the new species now being described first 

 appeared in November. I have no reason to think it had 

 been overlooked earlier because of its larger size and dis- 

 tinctive features. It is, however, rather local, not being 

 found in all the pools examined, although its range has 

 extended since first being observed. This species and D. 

 orientalis are the only two Gymnoplea which have been 

 seen in this locality during our visits, which have been made 

 fortnightl}-. A marked peculiarity of the new species is that 

 both antennse in the female and the left antenna in the male 

 have twenty-six joints ; I have not seen any Gymnoplea 

 described with more than twenty-five. There are other 

 differences from Diaptomus and Paradiaptomus, which will 

 be seen from the following description. 



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