366 PROCEEDINGS OF THE NATIONAL MUSEUM vol. lu 



hind femora (figs. 136, 137) greatly swollen, hind tibia heavily club- 

 shaped, apex obliquely truncated and surrounded by a row of stout 

 denticles; tarsi present on front, middle, and sometimes (Stibaropus) 

 hind legs, segment II subequal in diameter to I and III. 



Sternites: Sutures strongly sinuate or emarginate at level of ventral 

 trichobothrium; sternites III-VII each with two trichobothria (fig. 

 170), a small one posterior to spiracle and a much larger one antero- 

 ventral to spiracle. 



Terminalia: Male genital capsule (fig. 178) opening posteriorly; 

 female terminalia (fig. 187) deflexed so that ventral plates are con- 

 cealed by sternite VII. 



Type of subfamily.- — Genus Scaptocoris Perty (1830, p. 165). 



Distribution. — The distribution of this subfamily is that of its 

 two included genera, Scaptocoris and Stibaropus. Scaptocoris is 

 restricted to the Neotropical Kegion, where it is represented by not 

 more more than a half dozen known species; the smiilar number of 

 species of Stibaropus appear confined chiefly to the Oriental Region 

 with one species ranging westward through Asia Minor into south- 

 eastern Europe, and so are extralimital to this study. 



Discussion. — In addition to the definitive characters given above, 

 the members of the Scaptocorinae have a unique facies due to the 

 very strongly convex form. Of the above-enumerated features the 

 arrangement of the trichobothria, the shape of the sternal sutures, 

 the venation of the hind wing, and the elongated scutellum may be 

 considered fundamental or of phylogenetic significance. These, plus 

 the numerous other characters which are of a highly adaptive nature, 

 point to the group as a very specialized one. Together they emphasize 

 that the evolutionary path followed by its members is separate and 

 well removed from that traveled by other Cydnidae. 



The biology of the Scaptocorinae is very poorly known, but what few 

 facts are available will be treated under the species headings below. 



Scaptocoris and Stibaropus, although so widely separated geograph- 

 ically, are very closely allied, causing one to be more impressed by 

 their similarities than their differences. But to separate the two is 

 a relatively easy matter if one has recourse to the second labial; in 

 Stibaropus it is simple, while in Scaptocoris it bears a strongly folia- 

 ceous, semicircular lobe which is often hidden between the anterior 

 coxae. 



Genus Scaptocoris Perty 



Scaptocoris Perty, 1830, p. 165. 



Diagnosis.- — This genus, the only member of its subfamily in the 

 Western Hemisphere, may be recognized by any of the features 

 mentioned in the subfamily treatment above. The peculiar club- 



