hungerford: aquatic hemiptera. 205 



less than width. The interocular space behind and its width, including 

 the eyes, is very much less than half of the ver, large pronotum. 



'E.ytra clear brownish, a little darker on the middle of the disc. A 

 small yellowish point on the middle of the posterior border of the elytra. 

 Embolium yellow in all its width on the basal ^4, browTi at the extremity; 

 elytral margin behind the embolium imperceptibly sinuate, commissure 

 of clavus a half shorter than the length of the scutellum; connexivum 

 yellowish, hardly and very narrowly browmed in the sutures of the seg- 

 ments, with the posterior angles little prominent behind. Length, 7.7 

 mm. to 8 mm.; width, 4.8 to 5.2 mm. Mexico, Wyoming, California." 



Ainbrysus heidemanni Montd. 



Moutandon, Bui. Soc. Sci. Bucarest, 1910, SVIII, p. 18S. 



"Species very close as to form, mode of construction and design to 

 .4. monuon Montand, diflfering from it only m the size, a little more 

 feeble. 8.6 to 10 mm. ; in the lateral sides of the pronotum less dilated and 

 less strongly arcuate without, as well as the dilation of the embolium a 

 little less pronounced, the spines of the posterior angles of the seg- 

 ments of the connexivum a little less strong and less projecting although 

 always plainly visible, and in its deeper color, in design identical but 

 more extended, sometimes nearly black on the head and pronotum; the 

 scutellum and corium uniformly more or less deeply brown, with the mar- 

 gin of the embolium quite largely pale, poorly limited on its inner edge, 

 the basai angles and the apex of the scutellum pale; the segments of the 

 connexivum marked by a transverse black band covering up their basal 

 thirds. 



"The longitudinal median black band of the head quite enlarged, not 

 reaching clear to the anterior border, but behind, it sometimes extends on 

 all of the posterior part of the head from one eye to the other on a level 

 with the post.erior angles of the eyes. 



"Yellowstone Park in the puddles of water of the geysers. It is to 

 the kindness of Mr. Otto Heideman, the learned American Hemipterolo- 

 gist, that I owe this species which has enriched my collection. I have 

 also found a very dark specimen from the same locality in the material 

 of the National Museum at Washington. 



"The darker posterior part of the vertex is more often marked by a 

 median yellowish spot. The black blotches of the pronotum frequently 

 form two more or less triangular figures on each side, these very uneoual 

 figures sometimes united, sometimes very vague, with only the contours 

 indicated in places, but recalling always the same design as in A. morrncrn 

 Montand., and always much less emphasized with deeper color. 



"The margins of the pronotum as also the posterior border always 

 clear, the latter quite st^aieht, and marked sometimes by irregular black- 

 ish spots." Taken in Wyoming. 



Genus PELOCORIS, Stal. 1876. 



Stal, Euum. Hemip., V, pp. 142-144. 



These bugs do not have the head so deeply set into the prothorax 

 as the members of Amhrysas. Beak is very short. Posterior tarsi 

 shorter than posterior tibiae. The latter outside and inside equally broad. 

 Inferior side narrow, scarcely oblique. Eyes converging anteriorly, 

 inner margin distinctly sinuated. Anterior angles of pronotum extending 

 to the middle of the eyes. 



KEY TO SPECIES OF PELOCORIS. 



A. Ventral plate of the female genital segment "cleft" or emarginate 

 at tip. Prothorax stout, densely punctate. (Length, 8.2 to 9.6 mm.). 



P. carolinensis. 



