112 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. Ill 



bles much as in aeripennis, but in distal half the ventral margin of 

 inner face is straight rather than slightly convex. Basal segment of 

 each labial palpus with i to 3 setae. Eyes present. Presternum of 

 prothorax divided into 2 pieces (fig. 13, a). Episterna of meso- 

 thorax and metathorax without spinelike setae. One seta {atm, 

 fig. 23, h) on each side of middorsal suture (close to suture) in 

 anterior half of each thoracic segment and in the first 8 abdominal 

 segments. Mediotergites of abdominal segments i to 8 with prominent 

 setae unpaired. 



LUDIUS NITIDULUS (LeConte) 



Figures 13, a; 14, i; 23, a, b, e, g 



Corymbites nitidulus LeConte, Trans. Amer. Philos. Soc, vol. 10, p. 439, 1853. 

 Ludius nitididus (LeConte), Brown, Canadian Ent., vol. 68, p. 18, 1936. 



According to Brown (1936a, p. 19) this northern species is known 

 from the Atlantic coast as far west as Edmonton, Alberta. 



The larvae have been collected in New Brunswick from the litter 

 under spruce, in northern Saskatchewan from leafy debris in well- 

 established groves of aspen poplar (Popidus tremuloides) and from 

 the deep, damp litter under mixed stands of poplar, spruce, and 

 paper birch. On August 10 an adult with its larval and pupal exuviae 

 was found in its pupal chamber by the side of a poplar root about i 

 to i^ inches below the surface of the leaf litter. 



The larva is readily distinguished from its nearest relatives as 

 follows: Nasale and adjacent part of frons only slightly sunken; 

 nasale {n, fig. 23, a) broad, lateral denticles short and projecting 

 anterolaterad ; and outer prongs of urogomphi (fig. 23, e) twice as 

 large as inner prongs. 



Description of larva. — Length 14.5 mm. ; greatest breadth 2.5 mm., 

 on fourth abdominal segment. The largest specimen examined mea- 

 sured 17.5 mm. but even this larva may not have been full grown. 

 Body robust, with large membranes on lateral aspect; all segments 

 broader than long; head and ninth abdominal segment about two- 

 thirds greatest body width. Dorsum yellowish brown ("buckthorn 

 brown," Ridgway, 1912) ; darker on mandibles, nasale, talus, and tips 

 of prongs or urogomphi ; venter slightly paler. Dorsum slightly 

 rugose ; sparse shallow pits ; short, inconspicuous transverse rugae 

 (or pits) just anterad to transverse branches of impressions on 

 abdominal segments. 



Head subquadrangular with slightly arcuate sides; flattened above 

 and below. 



