ZOOLOGY 87 



Cleonus (Cleonopsis) pulverulus, Lee 



The lizards here are especially Crotaphytus collaris and 

 another. This association is also the home of the Western 

 Diamond-back Rattlesnake. I have never seen it in any other. 



The common towhee and the western blue-bird are charac- 

 teristic. The latter appears again in the Valley but is less 

 common there. It is absent from the mesa. 



SHORTGRASS OR -MESA" ASSOCIATION 



This includes the arid grasslands or steppe which is en- 

 tirely or nearly free of trees. In the vicinity of Albuquerque 

 this association is coextensive with the comparatively uni- 

 formly sloping monoplain known locally, as elsewhere in the 

 southwest as the "mesas. " To the northwest and elsewhere in 

 the Territory these "mesas" (not of course true mesas) may 

 rise higher and be occupied by the Cedar or even the Pinon 

 Associations. For the sake of brevity we have used the name 

 "mesa" to designate this treeless, grassy steppe. Faunistic- 

 ally we will recognize three subdivisions. The higher parts, 

 where the precipitation is greater or where there has been 

 less serious over-grazing, are covered by a very good growth 

 of grass. The drier or most seriously overgrazed portions 

 have been invaded by the composite Gutierrezia to such an 

 extent as to deserve to be designated The Gutierrezia So- 

 ciety. The arroyos that cross the "mesa" form the third 

 subdivision. Many types occupy all these situations to an 

 apparently equal extent. These we will consider first. 

 THE "MESA" GENERALLY. 

 ORTHOPTERA 



Trimerotropis vinculatus. This is preeminately i/ie.mesa 

 grasshopper being more numerous in individuals than all 

 other orthoptera combined. It ascends far into the mouths 

 of wider canons with the mesa type of flora and fauna. It is 

 common in the Cedar Ass'n., and ascends even into the Yel- 

 low Pine Ass'n., but is by no means so dominant there. It 

 is fully as characteristic of the Crysothamnus Association. 

 It seems to be the common grasshopper over most of New 

 Mexico. At least this is true from Silver City, Deming,, 

 Rincon, to Taos on the north and the continental divide on the 

 west, and Wagon Mound on the northeast. It is very vari- 



