ORTITOPTERA OF INDIANA. 175 



aa. Last ventral segment of the female abdomen, compressed so as to 

 form a carina or ridge on its under side, and divided so as to be 

 bi-valved; fore femora armed beneatli with many spines on the 

 inner margin Periplanetin.e, p. 191 



Sub-family BLATTIN^. 



In this sub-family the body of the male is elongate; that of the 

 female usually distinctly broader. The head is strongly depressed 

 and almost wholly covered by the pronotum. The antennire in our 

 species are setaceous. The posterior border of the pronotum is 

 truncate or rounded. Both pronotum and tegmina are free from 

 hairs. The tegmina are coriaceous or membranaceous, rarely corne- 

 ous, in texture. The median vein of the wings sends but few branches 

 to the apex; while the radial vein emits many parallel, simple vein- 

 lets to the costal margin. The tarsi are without pulvilli or pads. 

 The last ventral segment of the female is relatively plane, not com- 

 pressed or divided. The supra-anal plate of both sexes is but little 

 produced, triangular, entire. The sub-genital plate of the male (ex- 

 cept in the genus Blattella) bears a pair of minute styles. 



To this sub-family belong all the native species of roaches found 

 in Indiana, and one common introduced species, Blattella germanica 

 L. The native species, as far as synonymy goes, are a badly mixed lot 

 — so badly mixed, in fact, that more time has been spent upon them 

 than upon any other group treated in this paper, and in the end the 

 results are more unsatisfactory and less certain than in any other. 

 This is due to the fact that the sexes differ so widely in appearance 

 that they have been described as different species, and often placed 

 in wholly different genera. Most of the descriptions have been made 

 by foreign entomologists, who never saw a specimen in the field, and 

 for that reason knew nothing of the relationship of the dift'erent indi- 

 viduals before them. However, the two sexes are so seldom found 

 mating, that even the field naturalist can not be certain as to their 

 relationship. I have collected Indiana Blattidce for 15 years, and, 

 as yet, am only positive as to the sexes of one of our native species — 

 Temnopteryx deropeltiformis Brunn. The conclusions at which I have 

 arrived regarding the others are based mainly upon finding both -sexes 

 at the same time beneath the same hiding places on a number of occa- 

 sions. This, however, is not positive proof that the sexes belong 

 where I have placed them. 



Saussure, followed by Scudder, has stated that the tegmina in both 

 sexes of the genus Temnopteryx are abbreviated, yet this is not true 

 of T. deropeltiformis Brunn., the only one of the United States spe- 



