362 THE CANADIAN ENTOMOLOGIST 



Abdomen — Oval or somewhat conical; nota clothed above 

 with short rcclinatc bristles, beneath with slightly longer, almost 

 erect hair. Ventral plates, as a whole, with their sides converging 

 posteriorly; vestiture of first long and erect, that of second and 

 third short and decumbent except at sides. Posterior margin (;f 

 fourth notum dorsally, ilso sometimes ventr^iUy, usually of same 

 colour as genital segments, sometimes not so coloured. 



Chcetotaxy — Second segment without marginal bristles; third 

 with two, often very stout: fourth with complete row ending 

 ventrall}' in long hairs. 



Genital Segments — Prominent, often completely exposed, dull 

 orange. First, (g. s.l) large, often partially yellowish poliinose, 

 vestiture slightly shorter than that of second, "humps" almost 

 bare, in jirofile weakly curved, marginal bristles weak or hair 

 like; second (g. s.2) rotund, not flattened, anal area small and 

 not extending above middle of posterior surface. Forceps (f.) 

 darkened at least on distal half, in profile the fine, liairy vestiture 

 is seen extending almost to tips of prongs, which are strongly 

 curved forward and ajjproximatcd almost to tips but latter slightly 

 spread; base with upward llap-likc extensions clothed with fine 

 hair that is slightly shorter than vestiture of second segment. 

 Base of fourth ventral plate usually shows as a rounded ridge 

 the posterior extremity of which is slightly knobbed showing promi- 

 nently in profile, inner portion of lamellae at base thickly 

 set with short, stubby bristles forming a "brush." 



Genitalia — Distinctive. Accessory plates (a. p.) hairy; an- 

 terior clasp irs (a. c.) scarcely longer than posterior, (p. c. = pos- 

 terior claspers; p. = penis.) 



( 9 ) Females differ from males in the following important 

 charact( rs. 



Head — Breadth at front at narrowest part varies from about 

 five-sixths to same as eye width. Upper, inner orbits of eyes 

 diverging downward. 



Thorax — Bristly \estiture shorter. 



Legs — AH tarsi equal in length to tibia^. Posterior trochanter 

 with slender apical bristle: femur spindle-shaped; anterior face 

 essentially with but two rows of bristles, those of lower row few 

 and well separated, intermediate row may be represented by two 



