100 NORTH AMERICAN BLATTIDAE 



j-71 Length of Length of Width of Length of Width of 



body pronotum pronotum tegmen tegmen 



Asheville, North Car- 

 olina (40) 12. 7-13. 7 2.8-3 3-7-4 I4-4-I5-8 4-7-4-9 



Northern Illinois. .. . 14.7 3.4 4.3 16.7 5.7 

 St. Louis, Missouri . . 12.8 3 3.7 13.8 4.7 

 South Bend, Nebraska(5) 13. 8-1 5. 4 3.3-3.6 4.1-4.4 14. 3-1 5. 8 4.9-5.2 

 Arkansas City, Kan- 

 sas II. 7 2.9 3.6 12.8 4.3 



9 

 WoUaston, Massa- 

 chusetts 10.3 3.7 4.8 4.3 3.3 



Ivy Hill, Pennsyl- 

 vania (51) 10.9-12.5 3-2-3.7 4I-4-9 3-8-4-9 2.7-3.3 



Washington, District 



of Columbia (32) 10. 3-1 1.7 3.3-3.6 4.-4.6 4-44 2.8-3.1 



Rabun County, 



Georgia (2) 10.5-11.4 3.3-3.3 4.2 3-3-3-7 2.8-2.9 



Opelika, Alabama. . . 10.3 3.2 4.4 3.7 2.8 



Vigo County, Indiana (2) 10.8-11.6 3.2-3.4 4.4-4.7 4-3.8 2.8-3 

 South Bend, Nebraska(3) 10. 4-1 1.5 3.6-3.8 4.5-4.7 3.9-4.6 2.8-3.2 



Rather decided size differences are shown by the very extensive 

 series before us, these in great part due to individual variation, 

 though over certain regions somewhat different averages are found 

 to occur. No differences of adequate value or constancy are found, 

 however, to warrant the recognition of a geographic race. 



The average number of heavy spines on the ventro-cephalic 

 margins of the cephalic femora aid in distinguishing virginica from 

 Jtdvescens, and in consequence we have made the following counts 

 from one hundred females^^^ from all portions of the series before 

 us. 



Number of Spines 2-4 3-3 3-4 4-4 4-5 4-6 5-5 



Number of Specimens. ... 3 5 9 64 15 2 2 



Of these, 64 % have four spines on each limb, 81 % four or less, 

 while 98 % have four or less on at least one of the limbs. The 

 fifth or sixth distal, heavy spine, when present in this species, is 

 usually much smaller than the others. 



Coloration. — cf . (Normal.) General coloration ochraceous-buff , 

 with disk of pronotum slightly darker. Head tawny, eyes mummy 

 brown, ocelli pale ochraceous-buff, mouth-parts ochraceous-buff". 



"'^ This sex of these species is alone liable to be confused. In the males the spine count 

 agrees closely with that of the females. 



