CERAMBYCID BEETLE FAUNA 313 



specialization for life associated with plant roots (in this case, of 

 prairie grasses). 



The endemic Sonoran elements among the Cerambycidae are 

 almost entirely of early Neotropical derivation (in the geographic 

 sense) and exhibit various modifications of structure and habit 

 associated with the arid conditions under which they now exist. 

 They are characteristic of the Lower Sonoran Life Zone of Merriam 

 and occupy most of the central and northwestern plateaus of Mexico, 

 western Texas, much of New Mexico and Arizona, southeastern 

 California and eastern Baja California, and they are associated 

 with desert trees, shrubs, and Cactaceae, e.g., Anefliis, Osniidus, 

 Anepsyra, Rhodoleptus, Metaleptiis, Schizax, Tylosis, PUonoma, 

 Taranomis, Sphaenolhecus, Batyle, Moneilema, Peritapnia, Coenopiis, 

 and Glaucotes. Other genera, dominantly Neotropical, but well 

 represented in the Sonoran (and also in the Austro- Riparian) 

 are: Derobrachus, Methia, Elaphidion, Ophistomis, Euryptera, 

 Stenosphenus, Elytroleptus, Stenaspis, Dendrobias, Acanthoderes, 

 Oncideres, and Ataxia. A major derivative of the Sonoran fauna 

 occupies the intermountain area of the Great Basin. It is represented 

 by genera (e.g., Crossidius, Tetraopes, Mecas) associated with the 

 roots of shrubby Compositae ( as Artemisia and Chrysolhamnus) 

 and asclepiads. However, in the mountains, Eucrossus and Haplidiis 

 are present. These are endemic genera with southern affinities, 

 primarily associated with pinyon pine, which I have classed as 

 "Californian" in the broad sense. The small endemic subfauna, 

 designated by Van Dyke (1919) as the " Calif ornian"^ is also 

 deserving of brief discussion. In its restricted form it occurs from the 

 middle of the west coast of Baja California to Santa Barbara County 

 and in the interior from the San Pedro Martir Mountains to the 

 Tehachapi region of southern California (Fig. 2). This area is 

 characterized by many endemic groups of insects, particularly in 

 the Tenebrionidae, and corresponds generally to the center of 

 distribution attributed to the broad-sclerophyll vegetation of the 

 Pacific Coast by Cooper (1922), although many of the forest elements 

 included in his classification could be called " Vancouveran" on the 

 basis of the Cerambycidae associated with them. In a broader 



1 This term is applied in various senses by students of biogeography and ecology. 

 I have not attempted to determine priority of usage. 



