i9o8. CARFHNTnR.—Co//eml?o/a new to the Biitannic Fainia. 175 



food-plant seems to have had the effect of increasing enor- 

 mously the numbers of a hitherto obscure species of insect, 

 whose existence in the countr}- had been previously unsus- 

 pected. 



Fig. A. — Isotowa teuella — i, side view, X 75 ; 2, ocelH and post-antennal 

 organ of left side, x 520: 3, foot, X 520; 4, end of mannbrium, dens, and 

 mucro of spring, x 520. 



Isotovia tenella is a small springtail (fig A, i), measuring 

 onl}^ I mm. in length. The head as well as the dorsal and 

 lateral regions of the trunk are mottled with dark slaty blue, 

 the legs, spring and feelers being pale. In the main points of 

 its structure the species is a t^-pical Isotoma. On each side of 

 the head may be seen the usual eight ocelli and a long, narrow, 

 crescentic post-antennal organ (fig. A, 2). Towards the end 

 of the foot are two distinct clubbed tenent hairs (fig. A. 3), as 

 mentioned in the description given by Renter ('95, p. 28), not 

 one only, as shown in his figure. The claw is elongate, 

 simple and slightly curved, while the empodial appendage 

 ("lower claw^") is slender, pointed and almost straight. The 



