MORGAN HEBARD 93 



weighing all the evidence, however, we believe that they should 

 be given full specific status. Typical nehrascensis might be 

 supposed to represent the most distinct entity, ])ut in Arizona 

 the convergence of this species and iitcuini is very decided. 



Specific Diagnodic Characters 



The species of Myrmecophila do not show the numlier of specific 

 diagnostic characters usually fountl in the Orthoptera. We have 

 found little or nothing of such value in the North American 

 species, in size, form of segments, width of interocular space, 

 size of eyes, 2 length in proportion to width, form of caudal femora, 

 form of external male genitalia^ or form of ovipositor. 



In coloration certain factors appear to have decided value. 

 The species pergandei and oregonensis are dark, very rarely, in 

 specimens showing the maximum of recessive coloration, as pale 

 as darker individuals of nianui and nehrascensis. Moreover, 

 pergandei normally differs from formicarion in having the paired 

 generic pronotal spots faintly outlined in a paler shade of brown. 

 The species manni and nebrascetisis are pale, both developing a 

 weakly barred color phase, this appearing frequently in nehras- 

 censis in the eastern portion of its distribution, i-arely in manni 

 and only in the southeastern portion of its distribution. 



In the spination of the caudal limbs, nebrascensis shows a 

 decided difference from the other species, in having normally 

 one less spine on the dorso-intcrnal margin of the tibia and always 

 one less spinula on the dorsal sui-face of the metatarsus.^ The 

 in the proportions of some of the spines of the caudal limbs, as 

 other three species show slight, but apparently useful, differences 



- The eye. facets may show a different numerical range in the various spe- 

 cies. We have not used this feature, as in the majority of specimens the 

 eyes are partially hidden by the pronotum, while in many drying has affected 

 these minute areas to such a degree that the number can not be accurately 

 obtained. 



^ Insufficient alcoholic material is at hand to compare the concealed male 

 genitalia of the species studied. These parts are, however, very simple for 

 the one species examined and probably show no differential characters. In 

 an alcoholic specimen of nebrascensis examined, the large opening to the 

 seminal area below the anus was found to have its convex margins narrowly 

 chitinous on each side. 



^ We find that pergandei, oregonensis and tnantii have normally three, 

 rarely four, such spinulae; nebrascensis has two, lacking the median spinula. 



TRANS. AM. ENT. SOC, XLVI. 



