77G CHAELES PAUL ALEXANDER 



for Bittacomorpha clavipes (Hart, 1898 [1895] : 19 L). Careful breedings of 

 this species in 1913 at Orono, Maine, placed the indoor pupal life at four 

 days and eighteen hours, and that in nature at probably five days an 

 unusually short pupal duration. 



Larva. Length, when fully grown, 30-32 mm.; when fully extended, about 35 mm. 

 Diameter, 2-2.2 mm. 



Head light reddish brown, not marked with darker spots as in Bittacomorpha; body 

 whitish or pale yellow; tomentum short, pale; seventh and eighth segments of abdomen, 

 and breathing tube, light brown. 



Body almost smooth, sparsely clothed with short, appressed hairs arranged in indistinct 

 transverse rows, on intermediate segments of body there being about twenty of these rows; 

 body not at all tuberculate, as in Bittacomorpha. Prothoracic segment short, not so long 

 as mesothorax; metathorax nearly as long as preceding two segments combined. (In older 

 larvae that are about to pupate, the right pupal breathing horn may be seen coiled under- 

 neath the skin of the mesothorax.) First five abdominal segments swollen posteriorly into 

 a ring that completely surrounds the segments; first three abdominal segments with low, 

 indistinct pseudopods on either side of the median line, each with a small, recurved claw; 

 pseudopods after first pair more widely separated than, and not so well developed as, in 

 the Bittacomorphinae. Abdominal segments 4 and 5 more elongate, swollen posteriorly 

 but not bearing pseudopods; segment 6 narrowed behind, with a few scattered, outspreading 

 hairs; segment 7 narrower than preceding and telescopic within itself, a,t about two-fifths 

 the length there being a transverse row of long hairs marking the limit of telescoping; when 

 fully extended, segment 7 a little longer than segment 8; segment 8 a little narrower, and 

 telescopic basally into segment 7. (The parts of segments 7 and 8 which are exposed in 

 the retracted condition are brown and subchitinized, and bear scattered, outspread hairs 

 which are most numerous near the caudal end of the exposed part and here form transverse 

 rows; similar rows of sparse, setiferous punctures are on the dorsum of the swellings on the 

 first five abdominal segments.) Breathing tube (segment 9) retractile into segment 8 for 

 about one-fourth its length; when retracted, completely concealing gills. Tracheal gills 

 two, elongate-cylindrical, situated near base of segment 9; in normal position of rest, gills 

 usually projecting about one-half their length beyond end of segment 8. Apex of breathing 

 tube truncated but without well-defined lobes. 



Head small, proportionately much smaller than in Bittacomorpha; oval to somewhat 

 pear-shaped; narrow anteriorly, broadened behind, near posterior margin abruptly narrowed. 

 Prefrons broad, conspicuous. (As noted by most earlier writers on the genus Ptychoptera, the 

 head bears numerous punctures with setae which are plumose or havo a branched appearance 

 [Plate XV, 20]. The writer has examined numerous specimens under high magnification 

 and is inclined to believe rather that in some cases several bristles arise from a single puncture 

 and are closely approximated basally, altho free distally, and that the plumose appearance 

 is here merely apparent. In other cases, however, actual basal fusion has taken place. The 

 number of free tips from a puncture varies from three to six, five and six being common 

 numbers.) Labrum broad, transverse, on disk two large setiferous punctures bearing 

 branched setae; on either side beneath, conspicuous tufts of long hairs, these tufts continued 



