278 PROCEEDINGS OF THE NATIONAL MUSEUM vol.88 



projections slightly upturned and transparent, a small carina usually 

 present on dorsal side of each; metepisternum coarsely reticulated, 

 provided with a few very long setae on ventral half; metacoxae 

 semiglobose, glabrous, provided with scattered long setae except 

 on outer dorsal side; metafemora (fig. 12, e) glabrous, sparsely 

 covered by short pubescence, outer basal ventral tooth small, second 

 tooth smaller than basal one, two following teeth long, narrow, acute, 

 apical tooth subdivided to form two or three small indistinct ones; 

 inner tooth wanting; dorsal margin of metatibia sinuate where it 

 closes against two long femoral teeth ; apex of metatibia long, sharp, 

 slightly curved dorsad. 



Propodeum with numerous distinct carinae, those near base and on 

 disk arranged so as to form a double row of rectangles across disk, a 

 pair of conspicuous lateral projections present at posterolateral an- 

 gles of propodeum, spiracular openings almost vertical ; petiole short, 

 glabrous, basal lamina wide on ventral side, slightly narrower on 

 dorsal side, lateral carinae lacking; a few long lateral setae present 

 near apex of petiole; gaster slightly longer than metafemur; lateral 

 setae present on abdominal tergites 3 to 7; eighth tergite glabrous, 

 sparsely provided with short black or yellow setae, spiracular open- 

 ings round ; cercus small, round, located slightly nearer anterior than 

 posterior margin of epipygium, a small tuft of long setae ventrad of 

 each cercus; apex of ovipositor sheaths with long ventral and 

 lateral setae. 



Male: 5-5.5 mm. Antennal scape with mesal lamina produced 

 ventrad of antennal base (fig. 8, I, m) ; width of malar space slightly 

 less than one-third height of compound eye; combined widths of 

 compound eyes greater by one-third than width of interocular space 

 at level of antennal bases; metafemur without an inner tooth. 



Type locality. — Texas. 



Types. — Holotype, female, Victoria, Tex., July 15, 1918, ex Chlosyne 

 lacinia crocale.^ J. D. Mitchell; allotype, male, Devils Kiver, Tex., 

 May 2, 1907, F. C. Pratt; paratypes, E. H. Gibson, 1 female, Port 

 Lavaca, Tex., July 15, 1925, 1 female, Brownsville, Tex., Esprza 

 Ranch, August 18, 2 males. Holotype, allotype, and one female and 

 two male paratypes deposited in the U. S. National Museum; one 

 female paratype in Kansas Agricultural College, Manhattan, Kans. 



Host. — Chlosyne lacinia crocale Edwards (Lepidoptera, Nym- 

 phalidae). 



The nigricornis Group 



The nigricornis group is clearly related to the transitiva group 

 through the species S. nigi^cornis (see fig. 12, /, for the metafemur 

 of this species). This predominantly tropical group is related to the 

 femorata group through the species S. cowalis (Cresson). The pos- 



