38 FAUNA OF MAYFIELD'S CAVE. 



Bolitophila hybrida Meigfen. 



MEIGEN, Klassification, I, 47 (macrocera) ; Syst. Besch. Eur. zweifliigeligen Insckt., 

 I, 221, pi. vin (fusca) (Europe). ALDRICH, Cat. N. A. Dip., 1905, 147 (Europe 

 and White Mountains). 



This species is very abundant in twilight near the mouth of the cave 

 at times and is always common from near the mouth to " 19, " where 

 the drier part of the cave begins. It has twice been taken in the damp 

 portion of the cave between "23" and "28." 



Sciara sp. 



Probably 2 or 3 species. Not rare in the cave. Often seen but not 

 easily caught. Species of this genus are said to be very hard to deter- 

 mine and I got no specific determination from Mr. Coquillett, to whom 

 they were sent. Sciarse have been found outside the cave in the ravine, 

 under chunks of wood, etc. Within the cave they occur near the 

 mouth and through all parts of the cave. They are sometimes seen 

 flying about in the cave or resting on the wall. They also occur under 

 rocks and other debris, where they also breed. Their larvae live in 

 decaying organic matter. Two adults were reared in a bit of decayed 

 meat brought from the cave. 



Sciarae were taken in Truett's Cave also. This genus was recorded 

 from Mammoth, Wyandotte, and Bradford caves by Packard (1888, 80), 

 and from Wyandotte, Saltpeter, and Donnehue's caves by Aldrich and 

 Blatchley (1896, 186). Call (1897, 385) records Sciara inconstans Fitch 

 from Mammoth Cave, where it was found breeding in a rotten apple. 



Mycetophilidse have been recorded from Mammoth Cave, and Wyan- 

 dotte and Bradford caves in Indiana, a cave at Manitou, Colorado, 

 and Fountain Cave in Virginia, by Packard (1888, 21, 80), and from 

 Shiloh, Marengo, Saltpeter, and Donnehue's caves in Indiana (Blatchley, 

 1896, 186-191). They vary greatly in abundance in Mayfield's Cave. 

 On June 4, 1903, they were congregated by thousands just inside the 

 partition at the mouth, but by the last of September, when the next 

 visit was made, the number had reduced to normal, which is an average 

 of 1 to every 6 or 8 square feet on the walls and roof near the mouth. 

 They decrease in numbers rapidly farther in, and not many are to be 

 found in absolute darkness. They are found on the wall or ceiling of 

 the cave, where they are apt to congregate in any wide crack or depres- 

 sion. None except M. discoidea and Sciara were observed in situations 

 which could possibly suggest that they might feed in the cave. A single 

 specimen of the former was found under a rock where bait had been, 

 but it was not at the bait. Sciara breeds within the cave. These flies 

 may simply be sufficiently at home in the cave to hibernate there; to 

 wander in at various times and remain for a while; or they may feed 



