Sentence:  The Creatures that caſt their Skin are, the "Snake", the "Viper", the "Grashopper", the "Lizard", the "Silk-worm", &c. Thoſe that caſt their Shell are, the "Lobſter", the "Crab", the "Cra-fish", the "Hodmandod" or <WSD>"Dodman</WSD>", the "Tortoise", &c. The old Skins are found, but the old Shells never: So as it is like they ſcale off, and crumble away by degrees. 
Meaning of the word marked with <WSD> tags:  Any shellfish which casts its shell, such as a lobster.