155 



scribed from the Middle Silurian of France.* Between seventy and eighty 

 fossil species of the family are known, principally from the Mesozoic 

 formations, but some from all above the Middle Silurian. Mr. S. H. Scud- 

 der, of Cambridge, Mass., an eminent authority on insect paleontology, 

 says of the cockroach : " Of no other type of insects can it be said that 

 it occurs at every horizon where insects have been found in any numbers ; 

 in no group whatever can the changes wrought by time be so carefully 

 and completely studied as here ; none other has furnished more import- 

 ant evidence concerning the phylogeny of insects." 



Although abundantly represented in individuals, the Dumber of species 

 of Blattidse inhabiting the Eastern United States is comparatively few, but 

 twelve or thirteen having been recorded. Of these, seven, representing five 

 different genera, are known by the writer to occur in Indiana. Of the seven, 

 five are indigenous or native species, the other two having been introduced 

 from the Old World. 



In the present paper is given a synopsis of the genera occurring in the 

 state, together with the accessible synonymy and a brief popular descrip- 

 tion of each of the species. Such notes as have come to hand during 

 several years of observation, concerning the life history, distribution, and 

 habits of each species, are also added. 



A Synopsis of the Genera of Blattid.e Occurring in Indiana. 

 a. Sub-anal stylets present in the males. 

 b. Last abdominal sternite of the female divided; length of body more 

 than 22 mm. 

 o. Supra anal plate either truncate or pointed, and notched 



or cleft at the end I. Periplaneta. 



cc. Supra-anal plate rounded, entire at the end . .11. Ischnoptera. 

 lib. Last abdominal sternite of the female entire ; length of body less 



than 15 mm III. Temnopteryx. 



aa. Sub-anal stylets absent in the males ; last abdominal ster- 

 nite of the female entire. 



d. Body broad, the greatest breadth more than one-half 

 the length ; tegmina not reaching the tip of abdo- 

 men IV. ECTOBIA. 



dd. Body narrow, the greatest breadth about one third 

 the length ; tegmina reaching to or beyond the 

 tip of the abdomen V. Piiyi.lodromia. 



-Scuclder. Bulletin r. 8. Geog. Survey, No. 31, page 103. 



