Mr. J. N. Ilalbert on Irish JlydracJiniJa. 



II. — Notes on Irish HydracJinida ; wiih Descriptions of a 

 new Genus and Two new Species. Bj J. N. Halbert. 



[Plate II.] 



The following paper contains vecon.ls of some species of new 

 or rare Hydrachnida selected from a large amount of material 

 found in various localities in Ireland during the last five years. 

 Of these species two appear not to have been previously 

 described ; one of them proves to be the type of a new genus, 

 while of the remaining species eight are here recorded for the 

 fir^<t time from the Britannic * area. 



It was originally intended to reserve the new mites for 

 description in a general list of the Irish Hydrachnid fauna 

 which is being prepared. Before such a list can be com- 

 pleted, however, it is necessary to carry out some further 

 collecting in certain parts of the country, and it seems more 

 satisfactory to record the new species without further delay. 



The most interesting of the new mites is one of which I 

 was fortunate enough to find fully developed specimens when 

 collecting last May in the south-west of Ireland. The species 

 in question seems to bean extremely isolated form, possessing 

 a combination of diameters which at once distinguish it from 

 any of the known genera. It would be easy to briefly define 

 a new genus for the reception of this mite by referring to the 

 structure of a very few organs, sucli as the palps, legs, &c. ; 

 in a group like the Hydrachnida, however, where there is 

 such a great variety of structural detail, it seems especially 

 necessary to rely on a combination of various characters in 

 the formation of new genera. 



I have to acknowledge the assistance of the Irish Fauna 

 and Flora Committee sujiported by the lioyal iSociety, ami 

 also of the same Committee when acting under the auspices 

 of the Boyal Irish Academy : several grants enabled me to 

 collect in distant parts of the country. 



The nomcnclatui'e used in the following list is that of the 

 'Tierreich^ (" Hydrachnidfe und Ilalacarida?,'' Piorsig and 

 Lohmann, Lieferung 13, 1901). 



* The use of the word Britannic instead of British for faunistie 

 purposes has been proposed by Professor G. II. Carpenter, as the latter 

 trrni is now so frequently used to distinguish records referring- to Great 

 lirilain alone (' Irish Naturalist/ vol. xv. p. IM). 



