Species may be either independent or related under the particular disclosure. Where species under a claimed genus are not connected in any of design, operation, or effect under the disclosure, the species are independent inventions. See MPEP § 802.01 and § 806.06. Where inventions as disclosed and claimed are both (A) species under a claimed genus and (B) related, then the question of restriction must be determined by both the practice applicable to election of species and the practice applicable to other types of restrictions such as those covered in MPEP § 806.05 – § 806.05(j). If restriction is improper under either practice, it should not be required.
For example, two different subcombinations usable with each other may each be a species of some common generic invention. If so, restriction practice under election of species and the practice applicable to restriction between combination and subcombinations must be addressed.
As a further example, species of carbon compounds may be related to each other as intermediate and final product. Thus, these species are not independent and in order to sustain a restriction requirement, distinctness must be shown. Distinctness is proven if the intermediate and final products do not overlap in scope and are not obvious variants and it can be shown that the intermediate product is useful other than to make the final product. Otherwise, the disclosed relationship would preclude their being issued in separate patents. See MPEP § 806.05(j) for restriction practice pertaining to related products, including intermediate-final product relationships.