560 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.46. 



should be merged. The most important instance of this is the group 

 of closely related genera Lihurnia, Kelisia, and a few other smaller 

 ones, which have been merged into one, Megamelus. True, this 

 makes a very large number of species in one genus, but I maintain 

 that it is easier to identify an unknown individual when these are all 

 in one genus and fully keyed than when they are scattered through a 

 number of genera which overlap and intergrade and only serve to 

 confuse the student. It is true, also, that between the extremes of 

 this large genus there is considerable variation, but unless satisfac- 

 tory and appreciable Unes of separation into genera can be drawn it 

 is far better to consider the group as a whole a genus and treat it as 

 such. A more detailed treatment of tliis matter mil be found under 

 the heading of Megamelus. 



A descripti(5n of a new species without figures to illustrate the more 

 important details of structure is in most cases almost worthless — often 

 worse than none at all. It seems to me that it would be better to 

 let a Delphacid go undescribed until somebody could figure it as well 

 as describe it, instead of pubhshing an inadequate descdption which 

 might fit several species as well as the one for which it was intended, 

 and thus establish a name of uncertain identity. Words may mean 

 several things and may be interpreted in several ways, but an accu- 

 rate figure can convey only the one image. Especially is this true of 

 the male genitalia. 



Accompanying and supplementing the following descriptions I 

 have added man}^ figures to illustrate exactly what was intended to 

 be conveyed by the wording. These figures have mostly been drawn 

 to scale, and wiU show the relative size of the insects. In most cases 

 these are merely outhne drawings. 



In the collections are a number of female specimens which appar- 

 ently belong to undescribed species, but I have chosen to leave most 

 of these unnamed for the present until their males are found, for the 

 description of a new species based only on the female is usually very 

 unsatisfactory in many groups of the Homoptera. 



EXPLANATION OF TERMS. 



Perhaps a brief explanation of certain terms employed in the fol- 

 lowing descriptions would not be amiss here, especially of the male 

 genitalia. Pygofers refers to the genital segment which usually is 

 in the form more or less of a cyhnder; the anal tube is the circular 

 piece surrounding the anal style, wliich is usually the most posterior 

 organ; the genital styles are the paired claspers witliin the aperture of 

 the pygofers and are very variable in shape; the j^^nis (so called), 

 when visible, projects ventrad from below the lower margin of the 

 anal tube. The other terms are easilv understood. 



