306 E. G. LINSLEY 



attached to these woodland associations exhibit both northern and 

 southern affinities. 



Chaparral, according to Axelrod (1948) in such genera as Arcto- 

 staphylos, Ceanothus, Cercocarpus, Dendromecon, Fremontia, Garrya, 

 Photinia, Quercus (scrub oak), and Rhus, has a large representation 

 in the Madro-Tertiary Flora. Close relationship is apparent with 

 the sclerophyllous associations now in California, Arizona, and 

 Coahuila. The Cerambycidae now associated with this formation 

 include several forms with southern affinities discussed below as 

 "Californian" as well as overflow species classed as Vancouveran. 



EVIDENCE FROM PRESENT DISTRIBUTIONAL PATTERNS OF 

 PHYLOGENETIC RELATIONSHIPS OF CONTEMPORARY 



GENERA AND SPECIES 



The modern Holarctic elements of the cerambycid fauna appear 

 to be more or less equally represented in the northern forests and 

 mountainous regions of Europe, Asia, and eastern and western 

 North America. Their distribution reflects Postglacial dispersal and 

 their hosts are largely spruces and other northern and high-elevation 

 Pinaceae or northern-type deciduous trees as Salix and Populus 

 (Salicaceae). In western North America these are the dominant 

 Cerambycidae of the Canadian and Hudsonian life zones, but occur 

 also in dilute form in the coniferous phases of the Transition and 

 Upper Austral life zones, and a few species are represented in the 

 high-altitude coniferous forests at least as far south as Guatemala. 

 Representative genera of this Holarctic fauna include: Asemum, 

 Arhopalus, and Tetropium of the Aseminae; Callidium, Semanotus, 

 Xylolrechiis, and Clytus of the Cerambycinae ; Toxotus, Pidonia, 

 Grammoptera, Leptura, and Anoplodera of the Lepturinae; and 

 Monochamus, Acanthocinus, and Pogonocherus of the Lamiinae. 

 In addition to genera, there are a number of species with a similar 

 circumpolar or Holarctic distribution. Among these are Tragosoma 

 depsarium (Linnaeus), Asemum striatum (Linnaeus)^, Arhopalus 

 rusticus (Linnaeus), Stenocorus inquisitor (Linnaeus), Acmaeops 

 pratensis (Laicharting), Pachyta lamed (Linnaeus), Judolia sex- 

 macidata (Linnaeus), and Saperda popidnea (Linnaeus). The last 

 of these is associated with poplar, the remainder with conifers. 



The recent neotropical elements, derived from areas of high 

 temperatures and humidity and attached largely to southern-type 



