AN UNKNOWN BIBIO OCCURRING IN ROSE-POTS. 1 15 



which appear ■' in swarms in June and October " (Guide to the Study 

 0/ Insects, 1869, p. 392). It has never come under my observation in 

 the autumn, and I know of no other mention than the above, of its ap- 

 pearance at that time. To an inquiry made of Mr. E. L. Keen, of 

 Philadelphia, who has been paying special attention to the Diptera, of 

 his knowledge of a second brood, the following reply was received : 



" I have been giving special attention to the BibioiiidcB, but I never 

 saw a specimen of Bibio albipennis in the fall — in fact not after July, 

 although in May and June there are swarms of them. This last Octo- 

 ber I took a few specimens of a small black species of Bibio in a shel- 

 tered ravine." 



An Unknown Species Occurring in Rose-pots. 



The larvaj of a species of BibiouidcB were found in large numbers in 

 rose-pots in New York city. When received, on the 13th of February, 

 they were already nearly full-grown. They had probably been taken 

 from a conservatory, the artificial temperature of which had hastened 

 their growth. 



They measured 0.35 of an inch in length, by about 0.05 of an inch 

 broad. Their shape was nearly cylindrical, without feet ; a rounded, 

 corneous brown head of rather more than one-half the diameter of the 

 body ; on each of the segments, a transverse row of short papillae, and 

 a row of larger ones curving at the tips, on each side of the body. 

 Their general appearance was so unlike the ordinary dipterous forms, 

 and so similar in the character of the head 

 and stigmata to some of the Coleoptera that 

 they were at first believed to be of that order. 

 Within a fortnight after their reception they 

 had all entered the ground to the depth of 

 about three inches, where they transformed 



F1G.2.'?.— Irr.aso and pupa of Aspis- . . . 



TEs. sp. ? Twice the natural size, to pupae having the appearance shown in rig. 

 23. The flies emerged after a pupation of about two weeks. They have 

 a general resemblance to Bibio albipennis, except in darker wings, 

 and they are only about one-half its size. 



Upon submitting them to a friend who was engaged in the study of 

 Diptera, he referred them to the genus Aspistes. There seems to me, 

 however, to be reasons why they may not belong to that genus. 



[Baron Osten Sacken, having seen these examples since the above 

 was put in type, has expressed his opinion that they may be but dwarfed 

 Bibio albipennis.'] 



