Date of this Version
Much of the confusion that has plagued the two species considered here originated from the failure of previous authors to examine pertinent type material. I made a special effort to examine types of as many names as readily available, and in addition appealed to a number of museums and individuals for the loan of (or information about) material of horridus and muricatulus in order to account for the range and variation of these taxa. C. horridus, although widely distributed, is by no means common and many - even large - collections have few if any specimens of it.
Material was loaned (or made accessible in situ) by the authorities of Auburn University, Auburn (AU); the British Museum (Natural History), London, U.K. (BMNH); the Carnegie Museum, Pittsburgh (CMP); the Canadian Department of Agriculture, Ottawa (CNC); Cornell University, Ithaca (CU); the Field Museum of Natural History, Chicago (FMNH); the Florida State Collection of Arthropods, Gainesville (FSCA); the University of Kansas, Lawrence (KU); the Museum of Comparative Zoology, Cambridge (MCZ); and the United States National Museum, Washington, D.C. (USNM).