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.gov website belongs to an official
government organization in the United States.
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information only on official, secure websites.
The colors on the map refer to continents and are represented in the table as presence of a group in the respective continental region. Photographs: (a) Heterocephalus glaber, Neil Bromhall/ Shutterstock.com; (b) Typhlonectes compressicauda and (d) Bipes canaliculatis, reptiles4all/Shutterstock.com; (c) Rhinotyphlops lalandei, Willem Van Zyl/Shutterstock.com.
