Horrid Monoxillo (Holoderma horridum: Gray, John E. 1830. A synopsis of the species of the class reptilia. Pages 1-110 in The Animal Kingdom Arranged in Conformity with its Organization by the Baron Cuvier, member of teh Institute of France, with Additional Descriptions of all the Species Hitherto Named, and of many not before noticed. Ninth Volume. Whittaker, Treacher, and Company, London, England. pp.); Warty Lizard (Helloderma horridum: Cooper, James G. 1869. The fauna of California and its geographical distribution. Proceedings of the California Academy of Sciences 4():61-81); Gila Monster (Heloderma suspectum: Coues, Elliott. 1875. Synopsis of the reptiles and batrachians of Arizona with critical and field notes, and an extensive synonymy. Report upon Geographical and Geological Explorations and Surveys West of the One Hundredth Meridian. Volume 5. ():585-633); Gila Monster (Heloderma suspectum: Yarrow, Henry C. 1875. Report upon the collections of batrachians and reptiles made in portions of Nevada, Utah, California, Colorado, New Mexico, and Arizona during the years 1871, 1872, 1872, and 1874. Wheeler, G. M. ed., Report upon Geographical and Geological Explorations and Surveys West of the One Hundredth Meridian in Charge of First Lieut. Geo. M. Wheeler, Corps of Engineers, U.S. Army, Under the Direction of Brig. Gen. A. A. Humphryes, Chief of Engineers, U.S. Army. Volume 5 (Zoology), Part. 4. US Government, Washington, D. C. 509-584pp.); Gila Monster (Heloderma suspectum: Yarrow, Henry C. 1882. Check list of North American Reptilia and Batrachia with catalogue of specimens in U. S. National Museum. Bulletin of the United States National Museum (24):1-249); Gila Monster (Heloderma suspectum: Schmidt, Karl P. 1953. A Check List of North American Amphibians and Reptiles. 6th Edition. University of Chicago Press, Chicago, Illinois. 280pp.);