80 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I25 



2. Six heavy spines in transverse row on dorsal surface of segment 2; ventral 



spines on segments 5-7 all simple ; terminal spines absent ; cocoon slipper- 

 shaped, with definite "collar". . . .Dyarella Vargas, Martinez, and Diaz, 1946 

 Twelve heavy spines in transverse row on dorsal surface of second abdominal 

 segment; segments 5-7 each with at least one of its ventral spines bifid; 

 terminal spines present but small ; cocoon without "collar." 



Notolepria Enderlein, 1930 

 (Simulimn (Notolepria) exiguiim Roubaud *) 



3. At least some of the abdominal segments with dorsal groups of contiguous 



teeth in form of "combs" 4 



None of abdominal segments with groups of teeth in form of "combs" 6 



4. Ventral spines on abdominal segments 4-7 ; terminal spines present, although 



small ; network of threads visible in structure of cocoon 5 



Ventral spines present on abdominal segments 5-7 only ; terminal spines ab- 

 sent; cocoon parchmentlike, threads not visible Hearlca Rubzov, 1940 



5. Abdominal segment 8 with at least 16 spines (rarely as few as 16 in 6*. (L.) 



downsi Vargas, Martinez, and Diaz) in transverse row; respiratory appa- 

 ratus composed of 8 filaments only ; thorax without granulosity. 



Lanea Vargas, Martinez, and Diaz, 1946 



Abdominal segment 8 with a maximum of 16 spines (rarely as many as 16 in 



vS". (S.) ochraceitm Walker) ; respiratory apparatus with fewer than, or 



more than, 8 filaments; when composed of 8 filaments {S. ochraceiim only), 



the thorax lacks granulosity Simuliiim, s. str. 



6. Respiratory apparatus composed of 4 filaments only; abdominal segment 6 



with transverse row of dorsal spines ; ventral spines present on abdominal 

 segments 4-7, simple or bifid ; terminal spines present, although small. 



Eusivtulium Roubaud, 1906 



(Simulimn (E.) aurcum (Fries)*) 



Respiratory apparatus composed of 8 filaments ; segment 6 devoid of dorsal 



spines ; ventral spines present on abdominal segments 5-7 only, all trifid ; 



terminal spines absent Byssodon Enderlein, 1925 



(Simulium (B.) benjamini Dalmat*') 



SPECIES OF THE SUBGENUS DYARELLA, BASED ON PUPAL CHARACTERS 



1. Respiratory apparatus of each side composed of 8 filaments 2 



Respiratory apparatus of each side with more than 8 filaments 4 



2. Respiratory apparatus with rather long, narrow basal stem from which arise 



two main trunks in form of V, each with 4 filaments emerging at different 

 levels; festoons on each side usually in form of 5 ribbons that are connected 

 to one another at their dorsal end by transverse bands, and i separate rib- 

 bon at anterior part of dorsal aperture ; festoons are so connected that their 

 dorsal margins form a straight line ; 3 trichomes on either side of midline 



of thorax ruhicunduhmi Knab 



Respiratory apparatus with short, wide basal stem with more than two trunks 

 ramifying from it; the branching of each trunk being closer to the base; 

 festoons less extensive 3 



3. Filaments arising in groups of 2-1-1-2-1-1 so close to the basal stem that each 



one appears to arise singly ; bases of two uppermost festoons on each side of 

 dorsal aperture almost contiguous to one another ; three simple trichomes 

 on each side of midline of thorax acatenangoerms Dalmat 



