772 Charles Paul Alexander 



posterior group being the longest and most dorsal in position; on ventral face, four punctures 

 on either side (Plate XIII, 8); prefrontal sclerite apparently lacking setae, but on the epicranium 

 proper, along margin of prefrons, a longitudinal group of six punctures on either side, the 

 anterior pair the longest. Labrum semicircular in outline, outer margin fringed with long, 

 stiff hairs; dorsal surface with two transverse punctures. Clypeus narrowly transverse, 

 with four setiferous punctures in a transverse row. Dorsal median part of epicranium 

 forming a subquadrate lobe whose lateral angles bear brushes of hairs; laterad of these angles 

 a rounded hollo-w overlapped by a flat, bilobed operculum (this may be some modification 

 of the antennae which should occupy about this position on the head). Mandible elongate, 

 strongly chitinized, tridentate, the apical tooth the longest and more acute than the others, 

 the middle tooth bluntly obtuse; inner posterior angle of mandible produced proximad 

 beneath outer lobe of maxilla into a bluntly rounded lobe; mandible with a group of curved 

 setae on scrobe near base, and a group of longer bristles lying distad and mesad of these 

 setae on dorsal face of mandible. Maxilla with base, in a position of rest, concealed beneath 

 head-chitin; palpus stout, antenniform, two-segmented, the basal segment short and stout, 

 the apical segment much shorter and narrower, with a small, lateral, sensory papilla; outer 

 lobe of maxilla produced cephalad as a stout, digitiform lobe which is densely hairy. 



Family Ptychopteridae 



Larva. — Body eucephalous, metapneustic, long and slender, the caudal end prolonged 

 into a more or less completely retractile breathing tube bearing the spiracles at the tip. 

 Lobes surrounding spiracular disk indistinct. Anal gills two, elongate-cylindrical, 

 unbranched. Integument with tiny hairs (Ptychoptera), or with shght warty pro- 

 tuberances (Bittacomorpha), or with conspicuous elongate tubercles (Bittacomorphella). 

 Pseudopods on abdominal segments 1 to 3 each bearing a curved claw. Head complete; 

 eyespots distinct. IMandibles opposed. IMentum many-toothed (Ptychopterinae) or merely 

 bilobed (Bittacomorphinae). 



Pupa.' — Usually with one of the two pronotal breathing horns greatly elongated, much 

 longer than the body (this may not be true in Bittacomorphella); in Ptychoptera and 

 Bittacomorpha it is the right horn that is elongated, the left being degenerated; in Bitta- 

 comorphella the right horn is degenerated. Tarsal sheaths all parallel in the Ptychopterinae, 

 the fore pair overlying the middle pair in the Bittacomorphinae. Abdomen covered with 

 setiferous tubercles arranged in transverse rows on tergites and stcrnites, and more or less 

 in longitudinal rows on pleurites. Cauda with a powerful dorsal median lobe near base of 

 segment 8. 



The family Ptychopteridae includes three genera falling in two tribes: 

 the Ptychopterinae including the single genus Ptychoptera, and the 

 Bittacomorphinae including the " phantom crane-flies," Bittacomorpha 

 and Bittacomorphella. The habits of these species are discussed below 

 in connection with the various genera. The following keys separate 

 the subfamiUes of the Ptychopteridae: 



