271 



characteristics are not a result of casual variation. Arrhenurus batti- 

 lifer Koenike, has not yet been recorded as a British species. 



7) Arrltenuriix afßitis Koenike. 



This rare species, hitherto recorded only from Germany and 

 Bohemia, occurred in the vicinity of Lough Derravaragh, Westmeath, 

 in May 1901. Allowing for local variation in size and colour, this 

 specimen agrees excellently with Dr. Koenike's description 4 . The 

 chief difference is in the colouring which in the German mite is de- 

 scribed as cinnabar red with brownish yellow legs and palps. In the 

 Irish mite the colour is greenish changing to violet towards the sides 

 of the body, and especially on the appendage, while the palps legs and 

 petiole (fig. 13) are pale blue. 



S) Arrhenurus sculptus n. sp. 



Allied to A. solidits Piersig, but differs in the appendage. 



Length about I mm. Colour greenish yellow, paler on coecal area, 

 with brown markings. Compared with A. solidus Piersig, a structural 

 difference will be found in the shape of the body appendage (fig. 14), 



Fia:. 14. 



Fig. 13. 



Fig. 13. A. affinis Koen. End of appendage showing petiole and hyaline membrane. 



X"3. 

 Fig. 14. A. sculptus n. sp. Dorsal view of posterior half of body with body appendage. 



which is much narrower and more sharply marked off from the main 

 body than it is in that species. The body is also more truncate in 

 outline. Fourth segments of the last pair of legs unmodified. 



Locality: The male, only, of this species occurred at Raheny near 

 Dublin, towards the end of April 1899. In the same pond with it, 

 were both sexes of the rare A. truncatellus Müller. 



4 Schriften der naturforsch. Gesellschaft in Danzig VII., Taf. 1. p. 1 — J. 



