584 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



VOL. 48. 



Fig. 7.— -Geniocerus hagenowi. Female antenna. 



This species differs from all those described by Ashmead in having 

 the petiole above not striate and by its being swollen medially. 



Genus GENIOCERUS Ratzeburg. 



To this genus Kourdumoff assigns those species formerly referred 

 to the genus Tetrastichus, which have more than one bristle on the 

 submarginal vein. This is unsatisfactory, since it brings together 

 species which have from one to four ring joints in the antennae. 

 In many of these species, the ring joints are so minute as to appear 



as one unless resolved under 

 a very high power. To 

 illustrate this point, I give 

 here an illustration of the 

 antenna of G. Jiagenowi (fig. 

 7), which under ordinary 

 magnification appears to 

 have one ring joint and a 

 detailed drawing, greatly 

 enlarged (fig. 8), showing 

 more plainly the four ring joints which occur in this species, both draw- 

 ings being made from a slide mount. Other species belonging to this 

 genus, as restricted by Kourdumoff, which I have examined, have 

 only one ring joint and still others 

 two or three, it being impossible, as 

 in Jiagenowi, to tell the correct num- 

 ber unless a slide mount is made of 

 an antenna. 



Mr. Girault has attempted to 

 divide this series, using the number 

 of ring joints together with the 

 median furrow on the mesoscutum. 

 Kourdumoff has pointed out that 

 this latter character is of abso- 

 lutely no value, since in a series of fig. 8.— geniocerus hagenowi. detail of 

 the same species specimens will be TSMALK ANTENNA TO SHOW EmG JOINTS ' 

 found with the furrow and others without it. In describing new 

 species I have, therefore, for the present simply used the divisions as 

 made by Kourdumoff. 



GENIOCERUS CHRYSOPAE, new species. 



Female. — Length about 1 mm. Dark green, antennae brownish 

 testaceous, with one ring joint (fig. 9); mesoscutum and scutellum 

 finely longitudinally sericeously lineolate, median furrow on meso- 

 scutum and median pair of furrows on scutellum indistinct, the latter 

 about one-third as far apart as length of scutellum; propodeum almost 



