THE DIADEMATUS GROUP OF THE ORB-WEAVER GENUS ARANEUS NORTH OF MEXICO (ARANEAE: ARANEIDAE) HERBERT W. LEVI ABSTRACT Among our commonest spiders are the large Aiancus orb-weavers. Eighteen species are found north of Mexico. They are redescrilied, their diagnostic characters ilhistrated, their ranges mapped, and notes on their habits recorded. Three species turned out to be new: A. loashingtoni from northeastern U. S. and eastern Canada; A. yiikon from Yukon Territory; and A. pima from the Southwest. INTRODUCTION Among the species included in the present revision are some of the commonest spiders of North America, although several Araneus species are quite rare. Collections were examined not only to get an idea of the variation and distribution of common species, but also with the hope of finding members of the rarer species. The enormity of the collections available slowed down the work immensely. Because of the urgent need for identifi-cation and information on the distribution of the common spiders, I am presenting separately the diademotus group of the genus Aroneus, some members of which have never been illustrated before. It may take many years before I have examined types of all names of the numerous genera placed within the family and the many species described in the genus Aroneus in the Americas. At present I do not know the limits of the genus and have not de-cided whether certain species are best included in the genus Araneus. The recognition of reliable diagnostic morphological features of species was one of the critical questions to be resolved. My conclusions agree entirely with those of Grasshoff (1968), but differ from those published by Archer (1951a, b). Archer tliought that the species can be diagnosed by the shape of one single sclerite of the male palpus, the median apophysis, and the ventral view of the scape and epigynum of the female. Perhaps these structures will prove of value in differentiating genera; they certainly are of quite limited value for species diagnosis. Also, I agree with Grasshoff that leg spines have doubtful value in separating males of Araneus spe-cies; they are extremely variable within populations (L. D. Carmichael, in manu-script ) . As in my revisions of theridiid spiders, long established names of common species were kept; changing them does not make sense. ^ ^ I am following the purpose of the International Code on Zoological Nomenclature as expressed in its Preamble, although other authors have oc-casionally in my opinion intei-preted individual pro\isions out of the context to obligate tlie changing of names. For many common North American species older names are available, but these often have doubtful application as the types have been lost, and interpretation of the usually inadequate description depends on the experience of the reader. Doujjtful also are many of the names used bv Chamberlin and Ivie (1944) in Bull. Mas. Conip. Zool, 141(4): 131-179, February, 1971 131
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