OSBORN AND BALL— STUDIES OF NORTH AMERICAN JASSOIDEA. 47 



roundingly bilobed. They are found in similar situations with those 

 of the first group, and while in appearance the lobate form of the ver 

 tex in the two groups is not strikingly different, yet when it is borne 

 in mind that in the first case the lobe is simply an inflation of the an 

 terior margin, while in the second it is the refiexed and elevated |)Os- 

 terior margin, the difference in form of the adult vertices is readily 

 understood. 



The third group is characterized by a transversely striated pronotum 

 on which the dark markings, if any, are in longitudinal bands and not 

 in round spots on the posterior half. The front is vevv broad and 

 suddenly constricted to meet the clypeus. The elytral nervures in the 

 terminal portion are usually darker and mure or less irregular, the 

 central anteapical cell extending beyond the others. The larvae are 

 light-colored with dark lines, small, compact form, with a rounded par- 

 allel-margined vertex very similar to that of the adults, and short, ele- 

 vated abdomen. They appirently prefer dry and exi)Osed situations. 

 This groujj includes the last five species, of which saugiiinolenta is 

 abundant and widely distributed and is closely related to the European 

 venosa and the South .American siojiata. 



SYNOPSIS OF THE SPECIES. 



Pronotum very finely, evenly granulated, posterior half of disc with two 

 round black spots slightly farther apart than those on the vertex. 

 B. Posterior margiri of vertex a regular curve or nearly so, vertex very 

 narrow or obsolete behind the eyes, spots on pronotum close to pos- 

 terior margin, sutural margin of elytra unicolorous. 

 C. 9segment slightly narrower behind than in front, without an 

 abrupt constriction ; posterior margm truncate ; J^ plates broad 

 at base, regularly narrowing to an acute tip. -Specimens usu- 

 ally unicolorous except for the four black spots. 

 D. Broad and stout, nearly 2 mm. wide ; elytra convex, short. 



4-piinctata, Prov. 



DD. Narrower, wedge-shaped, elytra longer proportionately. 



modesta, n. sp. 



CC. 9segment suddenly constricted and depressed near the mid- 

 dle; ^ plates constricted in the middle, the tip enlarged, 

 rounding ; specimens usually with strong accessory markings. 

 D. .Small, less than 4 mm. long, 9 segment broadly rounding 



behind constricta, V. D. 



DD. Larger, over 4 mm. long, elytra over i mm. longer 

 than body ; 9 segment with the posterior margin 

 much produced, side concave prodiicta, n. sp. 



