386 SIR J. LUBBOCK ON ANTS, BEES, AND WASPS. 



years old. In the following nests, viz. another nest of Formica 

 fusca, which I brought in on the 6th June 1875, one of Lasius 

 niger on the 25th July 1875 * and of Formica cinerea on the 29th 

 November 1875, there were no queens ; and, as already men- 

 tioned, no workers have been produced. Those now living are 

 therefore the original ones ; and they must be between six and 

 seven years old. I may add that in these nests there have been 

 for the last year very few deaths f . 



In conclusion, I may place on record a new species of mite which 

 I have found in nests of Lasius flavus, and of which Mr. Michael 

 has been good enough to draw up the following description. 



UrOPODA FOItMICARIiE, Sp. UOV. 



This species, although it falls strictly within the genus TTropoda, 

 and not within Kramer's genus Trachynotus as defined by that 

 writer, still in most respects, except the very distinctions upon 

 which the genus is founded, resembles Trachynotus piriformis 

 (Kramer) more closely than it does any other recorded species. 

 It is, however, decidedly different ; and is characterized by the 

 squareness of its abdomen, the thickness and roughness of its 

 chitinous dermal skeleton, and especially by the powerful chiti- 

 nous rdiges or wing-like expansions on the lateral surface between 

 the second and third pair of legs. 



Length, & and $ , about "95 millim. 



Breadth „ „ '55 „ 



The abdomen is almost square, but somewhat longer than broad, 

 and slightly narrowed at its junction with the cepbalothorax, from 

 which it is not plainly distinguished. The extreme edge is a 

 strong chitinous ridge bordered with a thick fringe of short, stout, 

 curved hairs, as in T. pyriformis. The dorsal surface of the cephalo- 

 thorax is also narrowed towards the front, and has a curved ante- 

 rior margin bent down so as to protect the mouth, as in that spe- 

 cies ; it bears a few of the same kind of hairs as the abdomen, and 

 has a chitinous thickening at each side. The abdomen rises almost 

 perpendicularly from the marginal ridge. There is a central de- 

 pression occupying the posterior half, or rather more than half of 

 the abdomen ; and at the bottom of this depression are transverse 

 ridges, the hinder ones nearly straight, and the anterior ones bent 



* The last of these died on June 15, 1881. 



t These ants died off somewhat rapidly, the last onfuly 23, 1881, 



