OSBORN AND BALL STUDIES OF NORTH AMERICAN JASSOIDEA. 87 



Driotura, n. g. 



Head short, transverse, obtusely conical, vertex over twice wider 

 than long, anterior and posterior margin nearly parallel. Eyes large, 

 two-thirds the width of the vertex, slightly wedge-shaped, broadest 

 next the vertex, narrowing and curving back around the sides of the 

 pronotum. Face broad and short, front narrowing to one-half its 

 former width on clypeus, conically inflated and slightly reflexed onto 

 the vertex above, giving the impression of a pointed vertex with the 

 ocelli back of the margin as in Tmobregmiis . Clypeus short, parallel- 

 margined, genae broad and strongly angled. Pronotum short, slightly 

 longer than vertex, transversely striated on posterior two thirds, pos- 

 terior margin nearly straight, the lateral margin continuing around and 

 below the e\e as \\\ Jassiis without a lateral carina ; abdomen short in 

 male, much inflated in the female, suddenly narrowed to the long 

 p\ gofers, which are considerably exceeded by the slender ovipositor. 

 Legs stout. Elytra coriaceous, coarsely rugose, occurring in two 

 forms: — brachypterous , in which their truncate tips scarcely cover the 

 second segment of the abdomen, as wide or wider than long, the cos- 

 tal margin being curved around under the abdomen, extending broadly 

 below the line of the eyes, anterior margin covered by the pronotum, 

 — in this form the wings are rudimentary: — macropterous , in which 

 they extend nearly to the tip of the ovipositer, broadly rounding be- 

 hmd. In this form the wings are fully developed and the pronotum 

 is emarginate at the humeral angles, allowing freedom of motion to the 

 elytra. 



Driotura robusta n. sp. (Plate IV, Fig. 4.) 



Brachypte7-ous form : Size and form of D. gammaroidea V. D. nearly, 

 slightly smaller and with longer vertex, mottled-gray with a transverse 

 light band on pronotum and another on face. Length, V, 3-3.5 mm.; 

 S\ 2.75 mm.; width, 1.25 mm. 



Vertex narrow, transverse, nearly parallel-margined, twice wider 

 than long, anterior margin rounding on the sides, confused with the 

 ])roduced front in the middle, surface finely granulated, eyes triangu- 

 lar, laterally narrowing and curving around the pronotum; face broad, 

 rounding, moderately short ; genae broad, their outer angles distinct ; 

 front parallel-margined above, then regularly narrowed to the clypeus, 

 broadly produced above and confused with the vertex; clypeus par- 

 allel margined, slightly longer than broad, lorae regularly rounding, as 



