92 NORTH AMERICAN MYRMECOPHILA (oRTHOPTERa) 



tarsus, are of great specific diagnostic value. It is surprising 

 to find that the otherwise careful and exhaustive work of Schim- 

 mer is faulty in this respect. ^ It is not surprising, considering 

 the cieai-ly superficial chai-acter of the work, that Scudder, in 

 his paper on the species found in the United States, the two 

 new species proposed in which are both found to be synonyms, 

 has comiiletely ov(M-looked the most important of the features 

 exhibited by this armament. 



For the genus, the armament of the caudal tibia and meta- 

 tarsus may be described as follows: Caudal tibia with dorsal 

 margins supplied distad with one external and three or four 

 internal spines; distal extremity armed with three pairs of spurs, 

 the ventral pair being minute and of equal length, in some species 

 so small that they are discernible only under relatively high 

 magnification. Caudal metatarsus supplied dorsad with two or 

 three (in some species individually varying to four) spinulae, 

 distal extremity armed with one pair of spurs. 



Specimens Examined, Methods and Conclusions 



In the present paper three hundred and sixteen specimens 

 have been studied, distributed as follows: one hundred and one 

 in the Wheeler Collection, one hundred and three in the Hebard 

 Collection, fifty-three in the United States National Museum, 

 twenty-seven in the Mann Collection, seventeen in the Davis 

 Collection, fourteen in the Academy of Natural Sciences of Phila- 

 delphia, and one in the Brooklyn Institute of Arts and Sciences. 



The measurements have all been taken under the microscope 

 at a magnification of twenty-three diameters; study of the material 

 i-cHiuired a nuich higher magnification. 



The color terms used are taken from Ridgway's "Color Stand- 

 ards and Nomenclature," as is our custom. 



It is evident that of the six described North American species 

 but foui- are valid. These are yergandei, oregoneyisis, manni and 

 nebrascensis. All ai-e very closel}^ related and may eventually 

 prove to be geographic races of one species. After carefully 



' Tlial autlior overlooks (lu> i)uii- of ininulc vcntro-dislal tibial sjjurs and 

 treats the iar^e dorsal i)air as part of the series of spines of the dorsal luarfiiiis. 

 It is true that, in (icirroriini, the \rd\r of ventro-distal tibial spurs are reduceil 

 to the riiiiiiiMiiiii size eiicc)untei-e(l in t h(> "-eiuis. 



