NO. 2041. THE INSECT FAMILY DELPHACIDAE— CRAWFORD. 561 



I desire here to acknowledge with hearty thanks the constant 

 assistance and advice which Prof. C. F. Baker has given to me in this 

 work, as well as his kindness in placing all his collections before me. 

 My thanks are, also, due to Dr. V. L. Kellogg, under whose supervision 

 tliis work has been done at the university, and to Prof. R. W. Doane, 

 also of this university. I wish to acknowledge, also, my thanks to 

 Dr. L. O. Howard for his kindness in procuring for me the material 

 from the United States National Museum for study. 



DESCRIPTION OF FAMILY. 



The following is a brief description of the principal characters of 

 the family Delphacidae : 



Small insects, var3nng from about 2 to 10 or 12 mm., rather 

 elongate; eyes large, hemispherical, usually deeply emarginate be- 

 low at base of antennae; head and thorax conspicuously keeled, 

 keels variable in number, extent, and prominence; frons usually 

 longer than broad; clypeus triangular; rostrum long; antennse al- 

 ways two-jointed, variable in form and length, with a long seta at 

 tip of II; ocelli two, at base of each gena near lower margin of eye. 

 Pronotum tricarinate, about as long as vertex, extending down on 

 each side almost to base of forecoxae; scutellum longer, acute between 

 elytra, three to five carinate. Legs rather long and slender; fore 

 and middle coxae long, almost as long as femora; hind coxae large, 

 stout, with a small tooth posteriorly; hind tibiae with two to five 

 lateral spiniform spurs or spines, and a large, movable spur (calcar) 

 at apex; latter variable in form from spiniform or cultrate to tecti- 

 form with margin dentate; tarsi three, basal one the longest. Elytra 

 of two types, brachypterous and macropterous ; former may reach 

 less than halfway to tip of abdomen or more, truncate at apex, 

 obscurely veined; latter longer than abdomen, often setigerous on 

 veins, venation variable; clavus with two veins jomed apically; 

 corium with three at base, all but one usually branched apically; 

 membrane with four to seven more or less branched veins. Wings 

 sometimes wanting or reduced, usually nearly as long as elytra, 

 hyaline and folded once. Abdomen about as long as thorax; male 

 genital segment usually more or less cylindrical, truncate at apex, 

 with a pair of claspers (genital styles) and anal tube within apertiire. 

 Female genitalia ventral, consisting of a long, usually cylindrical, 

 acute, ovipositor sheath which reaches to the tip of the abdomen; 

 anal tube at tip of abdomen. 



The following synopses are not as complete and satisfactory as 



they ought to be, but in many cases I have had only the inadequate 



descriptions to base them on, and consequently they may be more or 



less imperfect. Some of the American species I have not been able 



95278°— Proc.N.M.vol.46— 13 36 



