The North American species of the Cicindela maritima group are C. duodecimguttata Dejean; C. oregona LeConte; C. depressula Casey; C. repanda De-jean; C. Hirticollis Say; C. limbata Say; C. columbica Hatch; C. belissima, Leng; and C. theatina Rotger. The male genitalia of these species are described. The group is diagnosed and two keys are given, one based on non-genitalic characters, and the other based on features of the male genitalia. For each of the species duodecimguttata, oregona, and depressula the following are presented: synonymy, analysis of geographic variation in size, coloration, color pattern of elytra, and distribution. Descriptions of the subspecies of oregona and depressula are given. Hybridization between the species duodecimguttata and oregona is examined quantitatively by means of the hybrid index method and the data are presented in the form of histograms. The zone of hybrization lies on the eastern slopes of the Rocky Mountain System from Colorado to the Northwest Territories, and is about 50 miles wide in Alberta but is nearly 1,000 miles wide in northern Canada. Variation of external characters and shape of the median lobe of the male is greater in the region of intergradation than it is within the range of the pure parental forms. Temporal variation occurs in hybrid populations. Phylogenetic and zoogeograph-ic relationships are postulated to explain the structural similarities and distribution patterns of the North American species of the maritima group.