62 Mr. T. D. A. Cuckerell — Descriptions and 



those species until critically examined. A table is ofForeJ to 

 facilitate their separation : — 



Fnnales. 



Black mark on first abdominal se.o-ment distinctly 



triangular, the lateral corners pointed lunatus, Say. 



Black mark on tirst abdominal segment a traiis- 



■verse band 1. 



1. Anterior femora red segregatus (Ckll.). 



Anterior femora black, or black with a red stripe. 2. 



2. Pleura hairy all over, though more thinly below. Townsendl, Ckll. 

 Lower part of pleura bare helianthi, Rob. 



Males. 



All, or nearly all, of the abdominal bands narrowly 



interrupted suhlunatus, Ckll. 



The bands beyond the first segment all, or nearly 



all, entire 1. 



1 . Larger ; anterior femora black ; pleura hairy all 



over Fraserce (Ckll.). 



Smaller ; anterior femora red and black, or red . . 2. 



2. Pleura hairy all over Tounisendi, Ckll. 



Lower part of pleura bare or little hairy segregatus (Ckll.). 



Triepeolus suhlanatuSj sp. n. (^Cressonii, Rob.^ race?). 



(^ . — Length 11 mm. 



With a relatively long and narrow, cylindrical abdomen. 

 Hair of face distinctly yellowish. Labrum, basal part of 

 mandibles, and first three joints of antennae red ; the two 

 stripes on mesothorax very clear and distinct ; no band along- 

 anterior border of mesothorax, or patches of hair in the ante- 

 rior corners ; tegulse bright ferruginous. Wings dusky ; 

 lower part of pleura with a bare, very densely punctured 

 patch. Legs red, the anterior femora black, with the apex 

 and the lower edge red ; middle and hind femora with much 

 black in front; spurs of middle and hind legs black ; trans- 

 verse band on first abdominal segment with broad anterior 

 and posterior projections, the latter dividing the apical light 

 band ; all the abdominal bands practically of the same colour. 



By the colour of the tegulge this species is like T. occidentalism 

 Cresson, but it differs from that by the dark femora and inter- 

 rupted abdominal bands. In Robertson's table (Canad. Entom., 

 Oct. 1903) it runs to T. Cressonii, Rob., and agrees with the 

 diagnosis there given, except as to the pleura. According to 

 Robertson, Cressonii as found in Illinois is exceeding variable, 

 and it may be that suhlunatus represents a geographical form 



