240 PROCEEDINGS OF THE NATIONAL MUSEUM vol. iie 



13. Sternite 3 trapeziform, about as long as posteriorly broad, sides and pos- 



terior margin slightly concave (Panama) . . . S. musiphila, new species 

 Sternite 3 broadly subtriangular, rounded posteriorly, one-half to one- 

 third as wide as sternite 4 14 



Sternite 3 very small, not more than one-quarter as wide as sternite 4, 

 elongate with concave sides, dumbbell shaped; sternite 4 five or six 

 times as wide as long (Panama, Ecuador) . . . . S. tertia, new species 



14. Sternite 4 about four times as wide as long; sides of sternite 3 strongly 



concave, sternite 2 small (Ecuador) S. ecuadoria, new species 



Sternite 4 about two and one-half to three times as wide as long. Sides of 

 sternite 3 weakly concave, sternite 2 much narrower (Panama and Ven- 

 ezuela) S. shannoni, new species 



15. Facial plate with a rounded convex boss. Prosternum with a posterior 



triangular plate and a disconnected linear piece. Posterior pale abdominal 

 spot with a linear extension to the margin. Sternites 1 + 2 relatively 

 large, sternite 3 not sclerotized, sternite 4 small and elongate, sternite 



5 angular, trapeziform (Ecuador) S. eliimborazo, new species 



Facial plate flat 16 



16. Sternite 3 completely unsclerotized. Sternite 5 more or less rounded 



crescentic 17 



Sternite 3 with a distinct, even if small, plate 18 



17. Prosternum anteriorly narrow but not strictly linear. Sternite 4 smaller, 



clearly narrowed posteriorly; sternites 1 + 2 a circular dot; sternite 3 

 absent, or, rarely, represented by a minute sclerotized dot (Panama, 



Costa Rica, Mexico) S. xiphosternum, new species 



Prosternum with a very transverse posterior sclerotization, anteriorly not 

 visible above surface. Sternite 4 longer and less distinctly narrowed 

 posteriorly; sternites 1 + 2 transverse (Ecuador). S. amphora, new species 



18. Sternite 4 long, fully four times as long as broad; sternite 5 rounded cres- 



centic (Ecuador) S. ecuadoria, new species 



Sternite 4 not very long, at most three times as long as broad 19 



19. Sternite 2 large, rectangular; sternite 5 angular, sides straight 20 



Sternite 2 dotlike or, if slightly larger, diamond shaped; sternite 5 rounded 



crescentic 21 



20. Facial plate unusually transverse. Prosternum large subtriangular. 



Foretibia black. Abdominal pale spots very large. Sternite 4 rectangular 

 with anterior end almost pointed (Panama) . . . S. lepida, new species 

 Facial plate normal as in figure 7. Foretibia pale. Abdominal pale spots 

 smaller than usual. Sternite 4 subrectangular, rounded and somewhat 

 narrowed anteriorly (Panama) S. transversa, new species 



21. Abdominal pale spots square, very large; tergite 5 divided centrally by a 



pale line. Sternite 2 diamond shaped, angles pointing anteriorly and 

 posteriorly, nearly as wide as hindfemur; sternite 3 with posterior margin 

 straight, anterior end rounded, not quite as wide as hindtibia; sternite 

 4 with posterior margin straight, sides considerably convergent anteriorly 



where it is rounded (Panama) S. dissecta, new species 



Abdominal pale spots rounded; tergite 5 not divided by a pale line. Stergite 

 2 dotlike or rectangular. Prosternum with a short very transverse piece 

 posteriorly and a narrow anterior extension 22 



