THE CRANE-FLIES OF NEW YORK PART II 719 



various chitinized jaws, legs, heads, and other insect remains, the dis- 

 tended proventricular regions usually show a considerable amount of 

 sand particles and much plant tissue. 



The pupa 



When ready to pupate, the larva ceases feeding and becomes much 

 contracted and sluggish. The pupa is formed within the last larval skin, 

 which is then shed completely except in certain Cylindrotominae and a 

 'ew scattered genera in other tribes, in which cases the larval skin adheres 

 ;o the posterior end of the abdomen. The pupal existence is spent in or 

 lear the haunts of the larva. 



In the strictly aquatic genus Antocha the pupa lives in water in a silken 

 sase, respiration being accomplished by means of the many-branched 

 wreathing horns. The species of Elliptera and certain Dicranomyia 

 simulans, for example) approach this aquatic condition. The other 

 pecies of crane-flies with aquatic larvae known to the writer go to the 

 oil in order to pupate, this category including Eriocera, Hexatoma, Tip- 

 da caloptera, T. abdominalis, and many others. 



The pupae of some, at least, of the Cylindrotominae attach themselves 



plant stems for the purpose of pupation. The leaf -mining Dicrano- 

 nyia foliocuniculator pupates within the larval passages. The majority 



1 the limnobiine forms spend the pupal existence in silken cases to which 

 3ebbles and particles of debris or plant tissues adhere. 



The pupae of the Ptychopteridae have one of the two breathing horns 

 enormously elongated, the tip of this being projected above the water 

 evel into the air for respiration. Certain tipuline crane-flies have a some- 

 what similar development of the breathing horns, discussed later. 



The duration of the pupal existence is remarkably uniform thruout the 

 group, averaging from six to eight days. The following table illustrates 

 this for the more representative genera and species. Records which 

 have not been determined sufficiently close, and which as stated are 

 probably too long, are indicated by an asterisk. 



