270 



not been recorded by Continental workers. In general shape the body 

 of this mite is very like that of A. compactus Piersig, but as may be 



seen in fig. 9 the petiole is quite different in 

 Fig- 9. structure. 



6) Arrhenurus dilatatus n. sp. 

 Closely allied to A. battilifer Koenike, 

 agreeing with that species in general shape, 

 structure of the body appendage, genital area, 

 and epimeral plates — the fourth pair of the 

 latter are however larger than in a type of A 

 battilifer kindly sent to me by Dr. Koenike. 

 Length of the male 1,16 mm, breadth 

 0,88 mm. Colour green tinged with blue to- 

 wards the sides of the body, dorsal surface with a series of black mar- 

 kings. Palps (fig. 12) with simple bristle-like hairs arranged as in 

 figure, minute tactile hairs on the distal margin of the fourth segment 



Fig. 9. Arrhenurus omatits 

 George. End of body appen- 

 dage showing petiole and 

 hyaline membrane. X 73. 



Fig. 12. 



Fig. 10 



Fig. 10. Arrhenurus dilatatus n. sp. End of appendage of male showing petiole and 



hyaline membrane, x 73. 



Fig. 11. Side view of same. X 73. 



Fig. 12. Palps and capitulum of male. X 100. 



sharply angled. The specific characters lie in the shape of the petiole 

 and hyaline membrane. In battilifer the petiole is gradually and evenly 

 widened from base to the extreme side angles, but in the present spe- 

 cies this organ is swollen into a prominence, on each side, beyond the 

 middle giving the apex a truncate appearance. The hyaline membrane, 

 also, is broader than it is in battilifer , in the specimen figured this 

 measures about 0,2 mm across the apex. 



Locality: Raheny ponds near Dublin, October, 1902. 



Fully developed males of this species were found in this locality 

 on two occasions, which would tend to prove that the above described 



