MORGAN HEBARD 



101 



Study of the types and the material now at hand shows con- 

 clusively that formicarum is a synonym of oregonensis, as indicated 

 above. 



Very close affinity to M. pergandei Bruner is shown by the 

 present species. Under the former species a comparison is made 

 on page 98. Considering the variation shown and the weakness 

 of the degree of differentiation which has taken place, we would 

 not be surprised should further investigation, particularly breed- 

 ing experiments, show oregonensis to be synonymic with pcrgandei, 

 or at best a geographic race. To oregonetisis close relationship 

 is shown by M. ninnm Schimmer, under which species the two 

 are compared on page 105. 



For the present, however, we ])elieve it best to recognize the 

 four species, pergandei of the eastern United States, manni of 

 the western arid and semi-arid regions of the western United 

 States, oregonensis of the Pacific Coast and nebrascensis of the 

 central western and southwestern United States. 



Bruner, when he described oregonensis, had but one adult 

 example. His original description is correct as to the diagnostic 

 differences in color, when compared with pergandei, but incorrect 

 in stating that oregonensis is more slender. Scudder correctly 

 gives the uniform character of coloration for his synonymic 

 formicaruni and for oregonensis. That author is, however, in 

 error in giving as differential characters the stouter form and 

 flatter ])ody of "formiearum," when compared with pergandei, and 

 its lighter coloration, when compared with oregonensis, as well 

 as the difference in caudal tibial spurs between ''formicaru7n" and 

 oregonensis. These features are all valueless, as is clearly shown 

 by the present series, being wholly attributable to individual 

 variation. 



The following table of measurements shows oregonensis to be 

 of an average smaller size than pergandei, and to be subject to 

 an even greater degree of size variation than that species. 



Measurements {in milliinetcrs) 



Length 



Length Width Length Width of 



(^ of of of of caudal 



body body caudal caudal meta- 



femur femur'- tarsus 



Victoria, British Columbia.... 3.2 1.9 1.97 1.29(X1.53— ) 1.15 



San Juan Island, Washington. . 3.33 2.11 1.9 1.22(X1.56— J 1.1,5 



TRANS. AM. LNT. SOC, XLVI. 



