56 EDWARD P. VAN DUZEE. 



lated coniiexivum, the rows of dots on the venter, the narrow tip of 

 the scutellum, and by the sliglitly wider apex of the head. The 

 terguni is black in this species as in rugulom, with the sides and 

 apex green. The pronotum is depressed within the lateral Tiiargins 

 leaving the edges sharp, and there is a transverse linear elevation 

 occupying the position of the callousities. 



Described from twelve examples representing both sexes. Several 

 of these were taken by me at (irand Junction, Colorado, in July, 

 1900 ; five, received from Prof. Wickham, were taken by him at 

 Williston, North Dakota, June 8th and 9th ; one received from Mr. 

 Otto Heidemann was taken at Salt Lake City, Utah, June 14th, and 

 one was taken in Colorado by Prof. E. D. Ball. The two latter 

 came to me labelled Thyanta rugvlosa. 



Thyaiita brevis n. sp. 



Small, oval, convex. Head shorter and more narrowed toward the ape.x than 

 in any of the allied species, the edges hroadly sinuated before the eyes then con- 

 verging to the rounded apex. Head, pronotum and scutellum closely, evenly 

 and rather tinely punctured, tlie surface without the smooth sphncelated spots 

 frequently so noticeable in rugutosa and punctirentris. Pronotum convex, a little 

 impressed within the lateral margins which are sharp and nearly rectilinear or 

 very feebly sinuated anteriorly. Humeral angles almo.=t rounded. Scutellum 

 short with the apex proportionately broad. Membrane as long as the abdomen 

 in the females, a little longer in the males. Venter coarsely, rugosely, but not 

 deeply punctured. Color as in the allied si)ecies varying from bright pea green 

 to almost white. In green examples somewhat paler on the front of the prono- 

 tum, base of the scutellum, and beneath, especially toward the median line. 

 Membrane with two blackish spots at base placed on either side of the apex of 

 the scutellum. Mesosternum with a black spot on either side between the ante- 

 rior and intermediate coxse. Eyes, last joint of the antennse, and sometimes the 

 apex of the fourth joint, tarsi and apex of the tibise blackish. Connexivnm im- 

 maculate. Tergum black on the two basal segments. In fully colored examjiles 

 the thin retlexed edges of the pronotum are pale, becoming rosy on the humeral 

 angles. Length 5i mm., width across the humeri 3 mm. 



Descrii)ed from ten examples taken by me at Grand Junction, 

 Colorado, July 28, 1900. Like its congeners tliis insect becomes 

 pale or almost wliite when it occurs on the low whitish Atraplax 

 and other prairie vegetation growing on the parched deserts of the 

 arid regions. This is the smallest Thyanta known to me. It may 

 be recognized by its oval convex form, fine even punctuation, the 

 two blackish spots at the base of the membrane, and especially by 

 the short narrowed head. The spots at the base of the metnbrane, 

 although apparently always present in brevis, cannot be relied upon 



