THE GROUND OR BURROWER BUGS. 77 



border of elytra curved slightly inward near its apex, thus ex- 

 posing very narrowly the hind portion of connexivum ; mem- 

 brane not surpassing the abdomen, its veins scarcely evident; 

 osteolar tube slender, two-thirds the length of metasternal 

 plate, prolonged beyond the opening as a curved flattened semi- 

 circular lobe ; front tibiae but slightly expanded. 



Six species are known from North America, four occurring 

 in the eastern states. 2 :; They are very similar in aspect, and, 

 as the marginal bristles of head, pronotum and abdomen are 

 usually eroded, they present a difficult group for classification. 



KEY TO EASTERN SPECIES OF GEOTOMUS. 



a. Head distinctly and closely punctate; cheeks flat. 

 b. Larger, length 3.8 or more mm. 

 c. Disk of pronotum with a faint but very evident postmedian trans- 

 verse impression, rather coarsely and closely punctate through- 

 out except on a small median area; corium black; scutellum 

 distinctly punctate. 38. ROBUSTUS. 



cc. Disk of pronotum without transverse impression, punctate only on 

 sides; corium piceous-brown; scutellum smooth or nearly so. 



39. SUBPUNCTATUS. 



bb. Smaller, length not over 3.2 mm.; form elongate-oval. 40. uhleri. 



act. Head minutely or obsoletely punctate; cheeks subconvex; corium 



piceous-brown. 41. pennsylvanicus. 



38 (61). Geotomus robustus (Uhler), 1877, 390. 



Oblong-oval, subdepressed. Black, shining; antennae dark reddish- 

 brown, incisures paler; legs piceous; beak and tarsi reddish-brown. Head 

 as broad across the eyes as long, its apex bluntly rounded ; cheeks 

 densely, coarsely, confluently punctate, their margins narrowly recurved ; 

 tylus transversely wrinkled. Antenna; relatively stout, third joint one- 

 fourth longer than second, slightly shorter than fourth, fifth longest. 

 Pronotum subquadrate, convex, about one-fourth wider than long, sides 

 straight on basal half, curving in front of middle around the obtuse front 

 angles, their margins very narrowly reflexed, not concave or subex- 

 planate within; disk with a vague but very obvious broad transverse 

 groove behind the middle, the median area in front of this almost 

 smooth, elsewhere densely punctured, more coarsely so on sides. Scu- 

 tellum elongate-triangular, its apex very narrowly rounded ; disk 

 coarsely, shallowly and sparsely punctate, the apical third more finely 

 so. Elytra nearly throughout distinctly, rather finely and closely punc- 

 tate, the apical half of corium more sparsely so. Propleura coarsely 

 rugosely punctate; abdomen with sides finely striate, minutely punc- 

 tate. Length, 3.8—4.2 mm.; width, 2—2.2 mm. 



23 The Geotomus subglaber I Walker. 1S67. 150). is known only by the single 

 type specimen in the British Museum labelled "North America." The description is 

 not sufficiently distinctive for its proper placement, and the locality uncertain. It 

 is therefore not considered in this work. 



