98 FAMILY II. BLATTIDJE. THE COCKROACHES. 



ter from the orb of day ; for, like others of its kind, it is a night- 

 prowling insect, going forth only after darkness has come in 

 search of provender or a mate. Davis states that "at night, with 

 the aid of a lantern, it was often found walking about on low 

 bushes, for it is a fair climber in spite of its clumsy appearance." 

 When disturbed the adults emit a greasy liquid which saturates 

 the atmosphere for a rod or two in every direction with its repel- 

 lent odor. 



The Platyzosteria ingens and the P. salHilianus of Scudder 

 (1877a, 92, 93) are synonyms, the latter being based on the nymph 

 stage, with yellow borders of the notal segments, as was also 

 Periplaneta semipicta F. Walker (1868, 141). The writer (1902, 

 44, 217) first showed that saltalianus represented only the imma- 

 ture wingless stage of ingens, the latter name being reduced to 

 synonymy by Rehn (1903a, 277). Traces of the yellow pronotal 

 markings of the young are often found in the adults. 



III. PERIPLANETA Burmeister, 1838, 502. (Gr., "around" + "a 



wanderer." ) 



Large, stout species, having the antennae very long and slen- 

 der ; eyes less separated than are the antennal sockets ; pronotum 

 convex, with sides deflexed; tegmina leathery, extending beyond 

 apex of abdomen in both sexes, their front and hind margins 

 rounded; wings with costal veins frequently forking, ulnar vein 

 with a few basal incomplete branches; subgenital plate of male 

 symmetrical, its styles elongate, slender, set in sockets on the sides 

 near apex; lower front margin of fore femora armed with a row 

 of rather stout spines, longest near middle of base and with three 

 long, unequal spines near apex; lower margins of other femora 

 with stout, elongate spines; first joint of hind tarsi longer than 

 the others united; arolia small. 



Three introduced species of wide distribution and one native 

 one occur in the eastern United States. 



KEY TO EASTERN SPECIES OF PERIPLANETA. 



a. Color not shining solid blackish-brown. 



1). Supra-anal plate prolonged beyond the subgenital plate, its apex 

 rounded, deeply notched (Fig. 49, A, C, ); thorax yellow with 

 two large blotches of chestnut-brown; median dorsal abdominal 

 segment of male not modified. 31. AMERICANA. 



bb. Supra-anal plate not prolonged beyond the subgenital, its apex 

 truncate, feebly notched (Fig. 49, B,) ; median dorsal segment of 

 $ modified. 



