420 MEMOIRS OF THE CARNEGIE MUSEUM 



51. Hiiul femora with a black spot at apex beneath but not at base; abdomen conic ovate, the petiole 



scarcely thrice as long as thick S. media. 



Hind femora with a black spot at base and a black spot at apex ; abdomen fiisiformly pointed, the 

 petiole about twice as long as thick ; ? 'S'. cameroni. 



52. Abdomen conic-ovate, the petiole about thrice as long as thick ; legs immaculate S. enochi. 



53. Abdomen fusiformly produced, longer than the head and thorax united, the petiole very .short, wider 



than long S. fusiformis. 



54. Lateral mesothoracic lobes immaculate 60 



Lateral mesothoracic lobes maculate, or with a black spot or line ; front face of pronotum usually with 



a median black spot, variable in size, sometimes very minute but rarely entirely wanting. 



Scutellum with a central black line or spot and also with a black line across the base or in the 



basal suture ; sometimes with a large black spot at apex 55 



Scutellum without a central black line or spot 59* 



55. Hind coxse immaculate, except sometimes at apex 56 



Hind coxfe with a black spot above toward base. 



Hind femora with a black spot at apex S. femorata Fabr. 



56. Hind tibise outwardly entirely yellow 58 



Hind tibiiB outwardly more or less fuscous or black, not entirely yellow 57 



57. Hind tibise black or fuscous with a broad yellow band before the middle ; hind femora with three 



black spots S. urichi. 



Hind tibise black or fuscous at the apical third, yellow basally ; hind femoi-a with a black spot at apex 

 beneath ; axillfe black ; scutellum with a large oval spot towards apex ; abdomen conic-ovate, the 

 petiole about five times as long as thick ; eyes very large, occupying the whole sides of the head. 



S. axillaris. 



58. Hind femora with a black .spot at apex 59 



Hind femora immaculate. 



Scutellum with a central black line, the apex yellow ; middle mesothoracic lobe with a trans- 

 verse black line anteriorly S. trilineata. 



Scutellum without a central black line, the apex with a transverse black spot ; middle mesotho- 

 racic lobe with two triangular black spots anteriorly .S'. marshalli. 



59. Middle mesothoracic lobe with a club-shaped central black .spot that is connected with a black line 



across the anterior margin but not extending to the base of the scutellum ; lateral mesothoracic lobes 

 ' with a black line ; scutellum with a club-shaped median black spot that is connected with a trans- 

 verse line at base ; a minute spot in mesopleural furrow, the apex of hind coxse, a spot at apex of 



hind femora and spots or bands on dorsum of abdomen, black ; ? S. morleyi. 



59*. Some old species fall in here. 



60. Middle mesothoracic lobe with a central black line ; scutellum with a black line across the base and 



with the apex black, or with a slight median black line. 



Metanotum without a central black line 61 



Metanotum with a central black line. 



Hind femora with a black spot at apex ; abdomen fusiformly pointed, the petiole about 

 four times as long as thick ; antennae, except the apical joints, eight to thirteen, yellow. 



S. ajncalis. 



6 1 . Hind femora immaculate 62 



Hind femora maculate, a large black spot at apex and sometimes with a longitudinal black spot ; hind 



