fl.C/-V 



The Biology of the North American 

 Crane-Fhes 



(Tipulidae, Diptera) 



VI. The Genus Cladiira Osten Sacken 



By Charles P. Alexander 



Generic Diagnosis 



Larva. Form comparatively short and stout ; integument 

 provided with a delicate appressed pubescence: no distinct setae; 

 basal annulus of each of abdominal segments two to seven with a 

 transverse area of microscopic points arranged in long, transverse 

 rows. Last ventral segment with a Hattened lobe covered with 

 short setae, evidently an organ for shoving. Spiracular disk 

 entirely without lobes, the spiracles being situated on the exposed 

 dorso-caudal surface of the last abdominal segment. Head-capsule 

 relatively compact : frontal plate broad, only slightly narrowed 

 behind. Labrum quadrate, with conspicuous, oval, lateral arms ; 

 antennae two-segmented, the terminal segment elongate-oval : 

 mandibles of a herbivorous type, with an apical point and two 

 incomplete rows of teeth on the inner or cutting face; mental bars 

 widely separated, each bar provided with two acute teeth at its 

 mesal end. 



Pupa. Cephalic crest gibbous, entire or feebly bifid, armed 

 on either side with a single powerful bristle ; two bristles on both 

 the front and vertex: labrum with pair of small bristles at each 

 cephalic-lateral angle ; labial lobes subquadrate, weakly separated 

 by the apex of the labral sheath : palpal sheaths short and stout, 

 straight ; lateral margins of eye produced laterad into a digitiform 

 lobe : antennal sheaths extending to opposite one-third the wing- 

 sheaths. Pronotal breathing horns lacking, entirely sessile ; pro- 

 notum and mesonotum armed with conspicuous bristles : wing- 

 sheaths ending opposite the base of the third abdominal segment ; 

 leg-sheaths long, ending opposite the base of the sixth abdominal 

 segment, the hind legs longest, the middle legs shortest. Abdominal 

 tergites with ten strong bristles, eight being arranged in a single 

 transverse row along the posterior margin ; abdominal pleurites 

 with four strong bristles, one on anterior ring, two near the caudal 

 margin of the posterior ring, one ventrad of the spiracle ; spiracles 

 rudimentary, situated on segments two to seven ; sternites unarmed 

 with bristles. 



Discussion of the Genus 



The genus Cladura was erected by Osten Sacken in 1859 

 (Proc. Acad. Nat. Sci. Phila., p. 229). The genus includes but six 



