267 



Cork, early in April, 1900. The body of this specimen was thickly 

 encrusted with a greenish matter, indicating that it had been hiber- 

 nating through the autumn and winter months. 



2) Hydrachna dissimilis n. sp. Q 



A species which may be compared with H. distincta Koenike 1 . 



Dorsal plates less curved, measuring 0,8 mm in length with the 

 anterior outer angles well marked. Skin covered with rounded scale- 

 like papillae. The fourth pair of epimera are narrowed towards the 

 inner posterior margins; the subcutaneous process instead of forming 

 a very narrow border, as in distincta, forms a recurved projection as 

 indicated in the figure. Genital area (breadth about 0,56 mm) much 



■ Fig- 4. 

 Fig. 3. 



Fig. 3. Hydrachna dissimilis n. sp. Q Left dorsal eye plate. 

 Fig. 4. Third and fourth epimera, both figures. X 31. 



broader than long, slightly indented on the anterior margin, and very 

 abruptly narrowed to apex, where there is a large circular opening. 

 Immediately over this opening there are four conspicuous ring-like 

 discs, arranged more or less in a line across the genital field. The 

 palps measure about 1 mm in length, more slender than in distincta, 

 with the second segment narrower and less irregularly swollen on its 

 outer margin. The rostrum measures about 1,24 mm in length, curved, 

 basal portion very large. Legs normal. 



Locality: Found in a brackish ditch on the coast of County 

 Wexford. 



3) Hydrachna biscutata Thor. 



Immature specimens of a species of Hydrachna agreeing with H 

 biscutata Thor, are not uncommon in Ireland. The nymph, only, has 

 been described, and from the fact that it is always found here in com- 

 pany with H. scutata Piersig, it seems not unlikely that biscutata may be 



1 I have to thank Dr. F. Koenike for a loan of his mounted type of H. 

 distincta Koen., for comparison with the present species. 



19* 



