300 



exception of the remarkal)le Alembracidae,) the pronotum is 

 considerably modified in the Derbidae, and in very many Ful- 

 g-oroidea is arched or rounded strongly anteriorly and most 

 frequently more or less deeply emarginate posteriorly. The 

 scutellum is nearly always 1-5 carinate in the Fulgoroidea, rare- 

 ly carinat^ in the Tetigoniidae and Cercopidae. It should be 

 noted that by "thorax." Stal means "pronotum" only. 



In certain forms of Derbidae (Philadclpkcia etc..) in which the 

 flight organs are very peculiar, the scutellum has lost its char- 

 acteristic triangular shape, with sharply limited margins and has 

 more the appearance of that sclerite in the Cicadoidea. 



It is so difificult to be sure of seeing correctly the empodia of 

 the tarsi, that 1 have omitted any notice of them. 



The venation in Siphonata is very difificult to homologize with 

 other orders; it can at least be done only by embryological 

 studies. At the present time, the nomenclatures of Stal, Fieber, 

 Edwards, West wood, etc., are used somewhat indiscriminately 

 and loosely. I have collated these and other systems as far as 

 feasible (being guided larg-ely by Comstock & Needham) and 

 have drawn diagrams to show the venation of various types. In 

 Scolypopa anstraUs. a Fulgoroid of the subfamily Ricaniinae there 

 are 8 veins given off by. or near, the basal cell of the corium. 

 5 from the apical margin ( Nos. 3 to 7) and 3 from the base, or 

 near it (Nos. t. 2 and 8). In order they are costal, subcostal, 

 radial, subradial, median, submedian. cubital, sutural. In the 

 clavus there are two, viz. : anal and axillary. In most forms the 

 subradial and submedian appear only as forkings of the radial 

 and median. 



The costal vein, as a rule, is present only near tbe base and 

 is lost later on in the subcostal which is usually, except near the 

 base, the marginal vein; in suc'h a case the costal is usually not 

 on a plane with the rest of the teg^men. m the Poekillopteridae 

 and a few others, the costal vein is complete, thoug'h' sometimes 

 subobsolescent as a thick vein. In the Cicadoidea, the sub- 

 costal and radial (and largely the obsolescent costal) are fused 

 more or less. 



The three main veins proceeding- from the apical margin of 

 the basal cell appear always to be (from the exterior inwards), 

 radial, median, cubital. These three are almost always easily 

 recognizable, though in most Tetigonioids and Asiracids the 

 first two have a somewhat long common stem, the medioradial: 

 on the other hand, in Ricaniinae we have 5 veins, here adding- a 

 subradial and a submedian. The sutural vein appears some- 



