Occlupanids are known for their morphological plasticity, but the subspecies of the toxodentid Eutreptosoma arcuatis are especially mutable. E. arcuatis shows an almost dizzying range of body shapes beyond that of most orthogonidectids. These forms are heavily localized and therefore uncommonly encountered by the average occlupanologist. The initial holotypes acquired by HORG come from occlupanologist M. Rutledge (FORC) from a corporate facility. Rutledge has since documented examples of each of these subspecies in the wild. Though the breadth of its forms may confound the most dedicated systematist, there are several attributes that connect this genus; First and foremost, they have a large, thick integument that invariably arches dorsally, and rarely lies flat. Secondly, they have colorful markings on both dorsal and ventral sides. Lastly, all E. arcuatis species share a similar small marking on their ventral side.