170 DR. G. S. BRADY ON DIAPTOMUS SANCTI PATRICII 



of any lateral process on its antepenultimate joint — also by 

 slight differences in the left fifth foot of the male ; from D. 

 graciloides by the contour of the hinder body segments as well 

 as by the character of the antennae and fifth foot of the male. 



The type specimens of D. Sancti Patricii were taken in 

 1865 in some of the small fresh-water loughs of Connemara. 

 Since that time it has not been observed until three years ago 

 (1909) when I found it abundantly in a pond at Heversham, 

 Westmorland. 



EXPLANATION OF PLATE XI. 



Fig. 1. Female seen dorsally X 84. 



2. Male seen from right side X 84. 



3. Median portion of right anterior antenna of male X 240 



4. Fifth pair of feet of male X 150. 



5. Fifth foot of female X 300. 



