1863.] 809 



proved by the hole on the outside and the pupa-case within; In a few in- 

 stances, there were on the outer surface of the gall, one or two holes, be- 

 sides the large one of Trijpcta. In one case, I had a curious instance of 

 the in-door life of insects. The Trypeta had already burrowed its hole 

 and was ready to escape, when a spider entered the gall through the hole 

 just completed and sucked out the fly. The contracted skin and the head 

 of the latter, as well as a cobweb, which I found in the cavity, plainly 

 showed the nature of the incident. lu the second group I placed some 

 less developed galls, which I take to be those of the same fly, but arrested 

 in their growth by the attack of a parasite. In one of them I found a 

 perfect specimen of an Eurytoma ; some others contained indistinct ex- 

 uviae of a pupa. The third group comprised the galls, produced by a lepi- 

 dopterous insect, which was proved by the frequent presence of the ex- 

 uviae of the pupa; in one case also by the remains of the perfect insect, 

 which had perished without having been able to escape; in another, by 

 the carcass of the caterpillar, apparently consumed internally by parasites 

 and crammed with the shells of their pupae, which thus prevented the skin 

 from collapsing. These galls are easily distinguished from those of the 

 Trypeta by their generally larger size, their more oblong form, their 

 much thinner walls, and consequently, the much wider hollow space 

 within. The section of the gall of Trypeta shows that its body consists 

 of pith, with a space in the centre, just large enough to contain the larva. 

 In the lepidopterous gall, on the contrary, there is no agglomeration of 

 pith and its walls are not stouter than those of the stalk. I leave to lepi- 

 dopterists the investigation of this gall, if it is not already known to them ■ 

 and will merely mention here that a gall, somewhat similar in appearance, 

 has been figured by Perris (Ann. Soc. Entom. de Fr. 3® Ser. Vol. IV, 

 Tab. 1, fig. Ill, 1. 2.) as being the produce of C(jchylis (Tortrix) Mlar- 

 ana H. Schaefi". 



Does Lasioptera produce a gall for itself, very similar in appearance to 

 the gall of Trypeta and therefore, perhaps overlooked by me, or taken out 

 of the box, before it reached me? Or does it colonize the galls of Trype- 

 ta, after they have been abandoned by their original owner? Or else, hrfore 

 the escape of the latter, the larvas of both species living in company? 

 All three cases are not without precedent in the history of CecidomyisR. 

 The burrows noticed above as occurring in some of the jT/y^je^a-galls may 

 perhaps be those of Lasioptera. 



The question remains therefore open for future investigation. The new 

 species may be described (from dry specimens) as follows : — 



