PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 635 



case ; though members of the California Academy who have written 

 on the subject assert that the motion is made by the pupa, which I 

 think very improbable. At all events the bounding motion is great, 

 as the little gall may be thrown 2 or 3 inches from the earth ; and 

 there are few things more curious than to witness, as I have done, 

 a large number of these tiny galls in constant motion under a tree. 

 They cause a noise upon the fallen leaves that may be likened to the 

 pattering of rain. 



WOTE ON CliUSTER FL.IES. 



By W. H. DALI.. 



Having heard several years ago of a fly which was a great nuisance 

 in the country houses near Geneva, N. Y., among members of my wife's 

 family living there, I requested information and specimens when it 

 should be convenient. Some time since a relative visited Geneva, and 

 on his return brought me some of these flies alive in a bottle covered 

 with gauze, which were exhibited at the last meeting of the Biological 

 Society and turned over to Prof. C. V. Eiley for identification. Since 

 then a letter has been received, from which I make the following extracts : 



"It is probably thirty years since the flies appeared in our neighbor- 

 hood. I remember little about it except that they were at once a terror 

 to all neat housekeepers, and from their peculiar habits a constant sur- 

 prise. People soon learned to lo«k for them everywhere; in beds, in 

 pillow slips, nuder table covers, behind pictures, in wardrobes nestled 

 in bonnets and hats, under the edge of carpets, and in all i)ossible and 

 impossible places. A window casing st»lidly nailed on will, when re- 

 moved, show a solid line of them from top to bottom; they are uncanny. 

 They like new houses, but are often found swarming in old unused 

 buildings and go regularly to church, or perhaps ouly a few good ones 

 abide in sanctuaries ; any way they are there. Best of all tbey like a 

 clean dark chamber seldom used, and if not disturbed form in large 

 clusters about the ceilings. With tliem are usually found a number of 

 purplish black hornets and some ladybugs ( Coccinella). They are very 

 cold and feel in the hand like small bits of ice. They are very oily; if 

 crushed, leave on the floor a great grease-spot. I hardly think they 

 breed in the houses, but do not know. About the 1st of April or as 

 soon as the sun shines warm in the early spring they come out in the 

 grass and fly up to the sunny side of the houses. Some possibly creep 

 in open windows, or if the house is closed and sealed they have a faculty 

 of going through any crack. They remain until some time in May, 

 then disappear, and no more are seen until about September, when they 

 come and remain as long as they are allowed to. They are very strong. 

 A powder that suffocates common house flies has very little effect on 

 them, and we attack them with ammonia and drown them with boiling 

 water; even then are not sure they are 'kilt entirely.' Very few are 

 found in the towns or villages ; they live in country places altogether. 



