 Other cases of (i) might be thought to be generated, irrespective of the necessity of the laws, by noting that a kind might be manifested in two or more superficially distinct species. Thus allotropes are distinct types of a single chemical kind that may differ considerably in superficial properties (for example, graphite and diamond, both types of the element carbon). Similarly, a caterpillar and a butterfly can be members of the same species. For known cases, D would have to be disjunctive. While that may not itself be problematic, it raises the epistemic possibility that the same phenomenon may be (nomically and metaphysically) possible for many kinds that we think exist in only one form.