261 



freely, usually within the tube-like threads, and frequently turn com- 

 pletely around in these, moving along with a gliding effect. They 

 do not move very rapidly when taken from the webs, and are very 

 fragile. Before pupation they spin an elongate cocoon, which is round- 

 ed at each end and consists of rather coarse outer threads and a com- 

 plete inner gelatinous envelope. To the surface of this inner cover- 

 ing, threads leading from the body are attached, these serving as a 

 means of suspension for the pupa. How the larval skin can possibly 

 be shed without detaching these threads I can not explain, but it is 

 done. The cocoon is itself suspended in a mass of rather loose 

 threads and forms a very pretty object when bedecked with tiny drops 

 of moisture, as it usually is in the damp situations where the species 

 occur. 



All the examples that I removed from the cocoons died in the pupal 

 stage — whether because of handling or from other causes I do not 

 know. 



HABITS OF IMAGINES 



The imagines of this family are taken more frequently upon flow- 

 ers than are those of Mycetophilidae, and they are not uncommon in 

 shady places in woods and amongst long grass on railroad embank- 

 ments, especially where old railroad ties are lying. 



CeropIvATus Bosc 



I have obtained the larvae of two species which I believe belong 

 to this genus and also the pupa of one, but unfortunately failed to 

 rear the species to maturity. The characters possessed by the larvae 

 are summarized herewith. The larva and pupa of a European species 

 (sesioides Wahlberg) are phosphorescent. 



GENERIC characters 



Larva. — Semitransparent, white, variously marked with purple. 

 Head as in Figures lo, ii, and 15, Plate XXXVHI; mandibles and 

 maxillae as in Figures 12 and 8. Body slightly flattened dorso-ven- 

 trally, the lateral margins slightly produced, somewhat bead-like. 

 Thoracic markings consisting of an irregular longitudinal stripe along 

 sides mesad of the lateral production, and usually a less clearly de- 

 fined narrow posterior band along the hind margin of each segment. 

 Abdominal segments with a dark band on each of the ele- 

 vated transverse ridges on each segment, the dark color ceasing 



