THE BACK-SWIMMERS. 



1057 



Fig. 213. Structures of Buenoa. 

 a, Male of B. limnocastoris Hung., X 6 ; b, beak of same, showing stridular ridges 

 on sides: c, inner view of front leg of same; 0, same of B. macrotihialis Hung., show- 

 ing the large femur and tibia ; e, egg of Buenoa in situ in stem of Juncus, a portion 

 of the stem removed ; /, inner view of front leg of B. margaritacea Bueno, showing the 

 tibial prominence and stridular areas : g, portion of front femur and tibia of same 

 greatly enlarged, showing stridular areas; h, same of B. scimitra Bare. 

 (a — / After Hungerford ; g — h after Bare). 



KEY TO EASTERN" SPECIES OF BUEXOA. 



a. Scutellum as long as or longer than pronotum, one-half or more the 

 length of claval commissure; claval orifice less than one-third the 

 length of scutellum. 

 b. Pronotum of males with four distinct depressions, thus appearing 

 tricarinate. 

 c. Stridular area on front femora of males small, oval, with not more 

 than 15 cross ridges (fig. 213, g) ; body smaller and more slen- 

 der; length not over 8 mm. 1196. margaritacea. 

 cc. Stridular area on front femora of males pear-shaped with about 

 25 cross ridges; body much larger and more robust; length, 

 8 — 9 mm. 1197. carinata. 

 66. Pronotum in both sexes with very feeble or no depressions; stridu- 

 lar area on front femora of male sword-shaped (fig. 213, h) , with 

 30 or more cross ridges; color straw-yellow without distinct 

 blackish stripes or markings. 1198. scimitra. 

 aa. Scutellum shorter than pronotum, not over one-third as long as 

 claval commissure; claval orifice one-third or more the length of 

 scutellum. 

 e. Smaller, less than 6 mm. ; interocular area very narrow, the eyes of 

 male subcontiguous at base ; sides of body with a black stripe 

 and apical third of elytra usually with black markings. 



1199. ELEGANS. 



ee. Larger, 6.2 — 7.5 mm. ; interocular area wider in both sexes, one- 

 third to one-half as wide at base of eyes as in front. 

 /. Pronotum of male not carinate, viewed from the side distinctly 

 arched and inflated; front femora and tibiae as in fig. 213, c. 



1200. LIMNOCASTORIS. 



ff. Pronotum in both sexes carinate; front femora and tibia? much 

 enlarged (fig. 213, d) . 1201. macrotibialis. 



1196 (1362). Buenoa margaritacea Torre-Bueno, 1908a, 238. 



Elongate, subcylindrical. Color above pearly-white to pale straw- 

 yellow, the scutellum in life usually orange-yellow; in dried specimens 

 the bases of pronotum and scutellum, and the elytra, in part, often with 



