256 NORTH AMERICAN BLATTIDAE 



This remarkable insect is distinctive among the species of North 

 American roaches in the pecuHar pronotum, which is thickened and 

 somewhat hooded cephalad; in the absence of tegmina and wings, 

 and in the production of the sixth dorsal and ventral abdominal 

 segments, which completely conceal the genitalia in both sexes. 



Characters of Male. — (Sulphur Springs, North Carolina.) Head flattened; eyes 

 not projecting, ocelli absent; face polished, with minute, scattered, microscopic 

 punctae. Maxillary palpi very short; fifth (distal) joint slightly longer than third 

 or fourth, with distal truncation not strongly oblique, extending only one- third the 

 distance from apex to base of joint. Pronotum polished, with punctae as on face, 

 roughened along borders of median depression and with numerous minute, rounded 

 projections in depressed area before the cephalic margin. Tegmina and wings 

 absent. Mesonotum, metanotum and dorsal surface of abdomen polished, with 

 minute, scattered, microscopic punctae, these more numerous laterad and on fifth 

 segment, accompanied by a few, minute, rounded projections on fifth segment. 

 Sixth dorsal abdominal segment triangularly produced; surface thickly supplied 

 with minute depressions and minute, rounded, projections; lateral margins cingu- 

 late, convergent to the weakly emarginate apex, this brief distal portion of the 

 free margin not cingulate. Supra-anal and subgenital plates and cerci situated 

 within orifice formed by the produced sixth dorsal and ventral abdominal segments. 

 Supra-anal plate not heavily chitinous, with free margins broadly concave laterad 

 at bases of cerci, thence convex convergent, the median portion of the plate strongly 

 produced, shield-shaped. Cerci stout, rather short, covered with minute hairs, 

 tapering distad to acute apex, the lateral margins entire, not crenate; dorsal sur- 

 face flat, ventral surface convex, joints obsolete. Within the anal chamber, sinis- 

 trad, is situated a short, stout, genital hook, bent inward at a right-angle mesad 

 and roughly rounded, with distal portion rather blunt. This genital hook springs 

 from the surface of one of the soft lobes which are found within the anal chamber. 

 Subgenital plate roughly scoop-shaped, produced, disto-laterad briefly and sharply 

 emarginate on both sides, from which emarginations spring small, elongate, 

 cylindrical, similar styles; between these the distal margin is rather strongly 

 convex. Sixth ventral abdominal segment produced to meet the sixth dorsal 

 abdominal segment; distal margin evenly convex; inner surface covered with a 

 soft integument, which shows no medio-longitudinal suture. Limbs, armament 

 of same, puhilli and arolia as given in generic description. 



Characters of Female. — (Sulphur Springs, North Carolina.) This sex is inseparable 

 externally from the male; without removing the sixth ventral abdominal segment, 

 it is sometimes impossible to determine the sex, but in frequent examples the inter- 

 nal surface of the sixth ventral abdominal segment is partialh' visible. Supra-anal 

 plate concealed as in male, of similar form and structure. Subgenital plate absent. 

 Sixth ventral abdominal segment as in male, excejit that the soft integument of the 

 inner surface shows a weakly indicated, medio-longitudinal suture. 



