Pertaining to the ranges of species that are contiguous but not overlapping.
                                                            
                                                     
                        
                                                
                        
                        
                            speciation Speciation in which the new species forms from a population contiguous with the ancestral species' geographic range.
                                                            
                                                     
                        
                                                
                        
                        
                            of distributions of two taxa or populations, having non-overlapping but contiguous ranges. cf. allopatric, sympatric.