94 FAMILY II. BLATTIM3. THE COCKROACHES. 



absent; tegmina leathery or strongly chitinous; subgenital plate 

 of male rounded at apex, that of female boat-shaped, its apical 

 portion valvular. 



This subfamily, as here characterized, corresponds to the Peri- 

 plauetinre of Scudder (1897, 12; 1900, 8). Three genera are rep- 

 resented in our territory. 



KEY TO EASTERN GEXERA OF BLATTIN.E. 



a. Tegmina in both sexes not reaching apex of abdomen. 



&. Arolia minute or absent, less than half the length of claws; teg- 

 mina covering about two-thirds of abdomen, strongly overlap- 

 ping, $ , represented by small oval, widely separated pads, 9 . 



I. BLATTA. 



bl). Arolia large, fully one-half as long as claws; tegmina represented 

 in both sexes by very short, subquadrate pads, either feebly 

 overlapping, or slightly separated at suture. (Fig. 43, C.) 



II. EURYCOTIS. 



aa. Tegmina in both sexes extending much beyond the apex of abdomen. 



III. PERIPLANETA. 



I. BLATTA Linnaeus, 1758, 424. (L., "An insect that shuns the 



light") 



Medium sized robust species having the antenna? elongate, 

 setaceous; interocular space, male, slightly wider than that be- 

 tween the bases of antennae; wings of female absent or greatly 

 reduced ; lower front margin of fore femora armed with numerous 

 rather stout, feebly curved spines which decrease gradually in 

 length toward apex, and with three larger unequal ones near 

 apex ; other femora armed beneath with fewer, stouter, more wide- 

 ly separated spines; joints 1 to 4 of tarsi each bearing a small 

 pulvillus, first joint of hind tarsi longer than the others united. 



29. BLATTA ORIEXTALIS Linnaeus, 1758, 424. Oriental Cockroach. 



Male Nearly uniform shining dark chestnut-brown; pronotum and 

 tegmina often slightly paler; legs and under surface dark chestnut-brown. 

 Pronotum suboval, widest behind the middle, its angles and sides broadly 

 rounded, disc with a broad impression each side on basal third. Supra- 

 anal plate twice as wide as long, carinate above at middle, its apex trun- 

 cate. Cerci short, flat or feebly concave above, widest at middle, their 

 tips acute Subgenital plate transverse, convex except near apex, the lat- 

 ter rounded. Styles slender, cylindrical, straight, equal in length to the 

 distance between their sockets and the base of subgenital plate. Female 

 Larger and stouter than $ , head wider, the interocular space greater. 

 Nearly uniform shining blackish-brown, the legs slightly paler. Pronotum 

 much larger, widest near base, the latter truncate. Supra-anal plate sub- 

 triangular, strongly keeled, its apex feebly concave. Subgenital plate as 



