:Yes I did. I have personally been on Isla Coronado and I saw two caliginis there. They are a small version of helleri, down to the wide dark band at proximal to the tail. This is typical island dwarfism. Murphy is probably correct about the two populations never meeting again but as of yet, they are not different species. Using Murphy's train of thought, I might as well describe the Catalina Island helleri as a unique species.
Too right. Especially when you consider that two mtDNA studies have shown caliginis to rooted within helleri. caliginis is a leaf on a twig of a branch of the C. viridis phylogeny. See link below, click on Crotalinae 2001 and Crotalinae 2000 links.
Quite frankly, retaining helleri simply as viridis while calling caliginis a different species is the best evidence there can be of the, ahem, inadequacy of this approach.