604 PROCEEDINOS OF THE NATIONAL MUSEU^f. vol.46. 



had used as the type of another new genus, Embolo-phora monoceros, 

 an African species. Therefore Lihurnia must be a synonym of 

 Emholophora, and the present wide usage of the former for the large 

 group of species is impossible. 



Moreover, EmboloyTiora monoceros is not congeneric with the group 

 of species in hand, as is readily seen by a study of the description of 

 the former. This name also must be dropped from our considera- 

 tion as a possible name for this genus. 



Among the names of the other "genera" merged with "Lihurnia,'' 

 the oldest tenable name is Megamelus, which Fieber erected in 1866 

 for a group of species which, in the estimation of some others besides 

 myself, are not generically distinct from the "Lihurnia" species. 

 Megamelus, therefore, must become the name of the great group of 

 species formerly known under the name of Lihurnia or Delphax, and 

 the type of the genus is M. notulus Germar, which Fieber considered 

 the type of his genus. 



Even supposing that Lihurnia were not a synonym of Emholophora, 

 it would be an open question whether or not it antedated Megamelus. 

 The only known date of Stal's Hemiptera Africana, volume 4, in 

 which he described Lihurnia, is 1866, with no month given. The 

 date of publication of the description of Megamelus is June 6, 1866. 

 Perhaps the latter antedates the former, but the settlement of this 

 point is wholly unnecessary. 



The following keys are based on rather variable characters often 

 and are intended only as guides in identification. Both alternatives 

 in many cases should be followed through in order to avoid any 

 error. Because of the meagerness of some descriptions and the lack 

 of figures it is impossible to include all the described species in the 

 keys. Those which are not included are, however, listed at the end 

 of the descriptions, together with then- bibliographical references. 



KEY TO THE SPECIES. 



a'. Lateral cariufe of prouotum rather straight, extending toward and usually to hind 

 margin. 

 bK Carinse distinct on apex of head, not or scarcely evanescent; vertex somewhat 

 produced before eyes. 

 c^ Frontal carinse whitish or yellowish, more or less completely margined with 

 black or brown. 

 d\ Notum brown, with a whitish median vitta extending to base of elytra; 

 latter with a brown area above apically; frontal black markings some- 

 times not prominent, or even subobsolete; median carina sometimes 



forked a little below apex of head albolineosus Fowler. 



d'. Notum without median vitta; elytra (macropterous) without brown area 



apically; color pale. 



e^. Frons conspicuously constricted above. 



/'. Frons very narrow, angulate at apex of head, diverging uniformly 



toward clypeus, three times as broad below as above; body rather 



large, elongate, whitish marginatus Van Duzee. 



