84 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 89 



free, decurved, and toothed at their extremities. Basally each second 

 valvula is connected by a single curved ramus {r2vl) with the an- 

 terior end of the corresponding second valvifer. The second valvulae 

 are moved back and forth by the rocking motion of the second valvi- 

 fers on their points of articulation with the ninth tergum. The 

 mechanism of the hemipterous ovipositor will be more fully explained 

 in the account of the two homopterous species to be described. 



AN AS A TRISTIS (dEGEEr) 



The abdomen of female Coreidae consists of lo segments, all of 

 which are visible and distinct from above (fig. 27 A), though the first 

 tergum is united with the second. The sternum of the first segment, 

 however, is absent (B), and the first ventral plate (//), therefore, 

 is the second sternum. It bears laterally a pair of spiracles. The 

 segments following, to the seventh, present no special modifications, 

 and the spiracles are located in the lateral parts of their ventral sur- 

 faces. The seventh segment of Anasa tristis has a broad tergal plate, 

 emarginate posteriorly (A, VII). The seventh sternum (B, VII) 

 is deeply emarginate, and bears medially a pair of small lobes (a), 

 at the bases of which is a prominent transverse groove. The terga 

 of the eighth and ninth segments are distinct though narrow plates 

 as seen from above (A, VIIIT, IXT) ; their lateral parts appear 

 ventrally (B) as two pairs of marginal lobes at the sides of the genital 

 region. The true sternal parts of these segments are covered by a 

 pair of large triangular plates (B, iVlf), which, as will presently 

 be shown, are the valvifers of the eighth segment. The tenth segment 

 (X) projects beyond the genital segments in the form of a short tube 

 containing the anal opening. 



The description of the abdomen of Anasa tristis by Tower (1913) 

 is wholly misleading, and has been the cause of considerable con- 

 fusion to systematists in Hemiptera. In the first place, the numbering 

 of the abdominal segments as given by Tower is at fault because the 

 first segment is entirely disregarded, though it is represented by a 

 distinct tergal plate (fig. 27 A, IT). The last pregenital segment, 

 therefore, is segment VII, not the sixth ; and the first pair of sub- 

 genital plates (B, a) are lobes of the sternum of this segment (VII). 

 The second and larger pair of genital plates (iVlf), apparently the 

 " eighth sternum " of Tower, are the valvifers of the eighth segment. 

 The ventral parts of the ninth segment are concealed, and the proc- 

 tiger, mistaken for the ninth segment by Tower, is the tenth segment, 

 numerically, though anatomically it may represent segments X and XI. 



