102 NORTH AMERICAN M YRMECOPIIILA (oRTHOPTERa) 



Length Width Length 



Length Widtli of of of 



O^ of of caudal caudal caudal 



bodv bodv fenuir femuri= meta- 



tarsus 



Lake Tahoe, California 3.13 2.11 2.11 1.10 (X1.S2-) 2.12 



Palo Alto, California 2 1.3 1.22 ^ (XL44 + ) .75 



Pasadena, California 3.13 2.04 



San Ysidro, California. . 2.88 1.97 1.77 1.19 (X 1.5 —) 



Length 

 of 

 9 ovi- 



positor 



Victoria, British Columbia..., 3.2G 2.27 1.9 1.22(Xl.56-) 1.56 



Seattle, Washington 3.54 2.04 1.84 1.1G(X1.59-) 1.5 



Divide, Oregon 2.86 2 1.77 1.22 (X1.45) 1.43 



Lake Tahoe, California 3.26 2 1.77 1.16(X1.53— ) 1.46 



Placer County, California 3.67 2.72 2.54 1.5 (Xl.69— ) 1.97 



El Dorado County, California. 2.79 1.74 1.63 1.04(X1.58 + ) 1.36 



San Francisco, California 2.52 1.63 1.54 1.02(X1.51— ) 1.29 



Alameda County, California... 1.5 1.02 1.02 .64(X1.59 + ) .82 



Palo Alto, California 2 1.43 1.22 .81 (Xl.51— ) 1.09 



Los Angeles County, California 3.06 2.15 2.11 1.23(Xl.71+) 1.41 



Los Angeles County, California 1.9 1.29 1.15 .73 (X 1.58+) .95 



Sierra Madre, California 2.86 1.5 1.32 .9 (Xl.47— ) 1.04 



San Ysidro, California 2.79 1.56 1.52 1.02(Xl.49 + ) 1.29 



San Ysidro, California 1.6 1.02 .88 .6 (X1.47+) .72 



In the series of females measured, the length of the caudal 

 metatarsus ranges from .4 in the smallest example to 1.29 mm. 

 in the largest specimen. 



The extreme variation in size of orccjonensis is most interesting. 

 Geographic distribution here is clearly a size factor. The material 

 fi'om British Columbia southward to northern California, and as 

 far as King's River in the Sierras, averages large ; that from the 

 region about San Francisco, south to the Mexican border, averages 

 small. The size of the host ants is, however, in some cases a 

 much more powei'ful factor in the size development of these 

 symbiotic crickets. An extremely depauperate condition is seen 

 to occur in nests of the small ant Tapinoma sessile Say. Speci- 

 mens taken in nests of that ant, in Alameda County and at San 

 Vsidi-o, arc very nmch smaller than any other adults before us. 

 Tiuit this is not a fixed rule for all material occurring with that 

 species of ant is shown by a medium sized adult cricket, taken 



'-' 'i'lic niiiiihcr of times Ihc width of the caudal femur is contained in its 

 IcMntii is also fiivcn. 



