190 Mr. T. Scott on 



Conthocamptus crassus appears to be generally distributed 

 and moderalely frequent in most of our inland waters from 

 Unst to Land's End, and it is one of the more easily recog- 

 nized forms. 



I am in doubt as to whether this species should be ranked 

 among the members of the present genus ; but as it seems to 

 be equally out of place in any of the other groups of Cantho- 

 camptinas, I thought it was better to leave it in the genus to 

 which G. 0. Sars assigned it. 



Genus Nitocra, Boeck. 



The species included under this genus resemble very 

 closely some of those in the genus Canthocamptus. The an- 

 tennules are usually eight-jointed ; the secondary branches of 

 the antenna are small and one-jointed ; the mandible-palp is 

 two-jointed, and the inner branches of the first pair of thoracic 

 feet, which are not much longer than the outer branches, are 

 three-jointed and prehensile. The inner branches of the next 

 three pairs are also composed of three joints. The prehensile 

 character of the inner branches of the first pair appears to 

 constitute the chief point of difference between Nitocra and 

 Canthocamptus. One British freshwater Harpactid has been 

 assigned to this genus. 



Nitocra hiberm'ca (G. S. Brady). 



1880. Canthocamptus hibernicus, G. S. Brady, Mon. Brit. Copep. vol. ii. 



p. 52, pi. xlvi. figs. 1-12. 

 1893. Nitoa-a hibernica, Schmeil, Deutschl. fi-eileb. Siissw.-Copep., 



ii. Teil, Harpact. p. 78, t. vii. figs. 1-16. 



I do not at present know of any Scottish station for this 

 species. Prof. G. S. Brady states that specimens were sent 

 1o him by the late David Robertson of Millport, who found 

 them plentifully in Mullingar Canal at Dublin and in a lake 

 near Newport, Co. Mayo. Mr. D. J. Scourfield has taken 

 Nitocra hibcrnica in a pond near London *. 



Genus Attheyella, G. S. Brady, 1880. 



The species included here under Attheyella have the an- 

 tennules short and usually eight-jointed; the secondary 

 branches of the antennge are small and one- (rarely two-) 

 jointed; roandible-palp small and composed of two articu- 

 lations ; inner branches of first pair of feet scarcely, if at all, 



• " Entomostraca of Epping Forest, Part II.," The Essex Naturalist, 

 vol. X. p. 260, tab. i. (1898). 



