"5. Basistyle without apical lobe (I-'ig. 76-78) 6 



Basistyle with apical lobe definitely developed (Fig. 

 80, 85) or represented by a mass of long hairs 

 (Fig. 81, 82) 9 



6. Basistyle with a thick brush of hairs, dh, on dorsal 



side (Fig. 77); basal lobe with a large area of 



hairs triseriatus 



hcndersoni 



Basistyle without a brush of hairs on dorsal side, but 



with a definite brush forming the basal lobe ( Fig. 



76, 78) 7 



7. Filament of claspette only about half as long as stem 



of claspette, similar to that in Fig. 9(.C 



atropalpus 



Filament of claspette approximately as long as stem 

 of claspette ( Fig. 76C) 8 



8. Basal lobe a distinct, raised prominence; basistyle 



considerably widened at basal lobe (Fig. 76) .... 



mitchellae 



Basal lobe represented by only a slightly raised disc- 

 like area; basistyle only imperceptibly widened 



at this point (Fig. 78) nigromaculis 



sollicitans 



9. Basistyle with a dense brush of long posteriorly 



directed hairs at apex (Fig. 81); basal lobe form- 

 ing a flat sclerite on mesal face of basistyle, the 

 lobe bearing a single long spine at its apex (Fig. 

 8M) aurifer 



Basistyle without a dense apical brush of long spines, 

 but with a well-developed apical lobe (Fig. 83); 

 basal lobe not as in Fig. 81/1, either projecting 

 from basistyle, or with a large spine at its base, 

 or 2 spines at its apex (Fig. 82/4), or without a 

 spine, sometimes with a cluster of long hairs. . .10 

 10. Integument of almost entire body yellow; stout spine 

 arising from base of basal lobe flattened and 

 widened at tip (Fig. 83B) fulvus pallens 



Integument chiefly dark brown or black; if a stout 

 spine arises from basal lobe, it tapers to a pointed 



tip (Fig. 84, 85/4, B) 11 



1 1. Basal lobe having 2 unusually long and fairly stout 

 hairs arising from apical margin (Fig. 100); fila- 

 ment of claspette irregular and appearing twisted 

 trichurus 



Basal lobe without such a pair of long and stout hairs 

 arising from apical margin; filament of claspette 

 either contorted (Fig. 84F), or not (Fig. 85C) 

 12 



12. Large stout spine of basal lobe situated on a sepa- 



rate elevated finger-like process (Fig. 84) 13 



Large stout spine of basal lobe either not on an 

 elevated finger-like process (Fig. 85) or absent 

 14 



13. Claspette forming a sinuate process without a dis- 



tinct division into a basal stalk and an apical fila- 

 ment (Fig. H4F) atlanticus 



Claspette distinctly divided into a basal stalk and 

 a sharply delineated curved apical filament, much 

 as in Fig. 96C tormentor 



14. Apical lobe with a large dense patch of spatulate 



hairs (Fig. 80) canadensis 



Apical lobe with hairs tapering evenly (Fig. 85) 

 15 



15. Basal lobe with 2 stout spines and many small hairs 



(Fig. 856); hairs near the 2 stout spines shorter 



than hairs on basal lobe in Fig. 86B dorsalis 



Basal lobe at most with only 1 stout spine, some- 

 times with some of the hairs on basal lobe very 

 long (Fig. 86B) 16 



16. Basal lobe appearing detached, joined to basistyle 



by only a narrow sclerotized strip (Fig. 87, 88B, 



89/1) 17 



Basal lobe forming a solid part of the basistyle (Fig. 

 90-98) 19 



17. Apical lobe small (Fig. 87) dupreei 



Apical lobe large ( Fig. 88 ) 18 



18. Filament of claspette wide, its lower basal corner 



produced into a definite angle. Fig. 89C; mesal 

 aspect of apical lobe long and narrow (Fig. 89/1) 



spenceri 



Filament of claspette narrower than that in Fig. 89C, 

 its lower margin almost continuous in outline 

 with the stem of the claspette; mesal aspect of 

 apical lobe shorter than that in Fig. 89.^, decidedly 

 ovate (Fig. 88/4) sticticus 



19. Basal lobe without a stout spine, having only abun- 



dant short hairs (Fig. 95) excrucians 



Basal lobe with a conspicuous stout spine or a group 

 of long hairs (Fig. 90) 20 



20. Filament of claspette having an upper point which 



is produced backward into a sharp basal barb 



(Fig. 90C) 21 



Filament of claspette without a barb (Fig. 92C), 

 at most with a sharp upper corner (Fig. 93C) 

 22 



21. Stout dorsal spine of basal lobe having an angulate 



thickening near its base (Fig. 90) infirmatus 



Stout dorsal spine of basal lobe evenly sinuate 

 throughout its length (Fig. 91) trivittatus 



22. Basal lobe composed primarily of an area of short 



hairs forming the basal portion of the mesal face 



of the basistyle ( Fig. 92, 93) 23 



Basal lobe represented by a distinct lobe projecting 

 mesally from the basistyle (Fig. 96-98) 24 



23. Area comprising the basal lobe long and triangular 



(Fig. 92); filament of claspette fairly short (Fig. 

 92C); no area of membrane present within the 



basal lobe (Fig. 92/4) flavescens 



Area comprising basal lobe shorter than that in Fig. 

 92, its lower portion somewhat projecting (Fig. 

 93); filament of claspette long and slender (Fig. 

 93C); an oval area of membrane present above 

 the stout spine (Fig. 93/4) stimulans 



24. Filament of claspette with an elongate narrow neck- 



like base (I-'ig. 97(7) grossbecki 



Filament of claspette without a well-differentiated 

 basal neck (Fig. 98C), or with a short one (Fig. 

 94C) 25 



21 



