Is a generic claim acceptable if a prior art claims a species that falls under that genus?

A generic claim is typically considered unacceptable if prior art includes a specific claim (species) that is encompassed by that generic claim, as it does not meet the novelty requirement set forth by patent law. When prior art discloses a species that falls within the claimed genus, it means that the claimed genus is not new. For a generic claim to be patentable, it must cover an invention that is distinct and new, which isn't the case here if a species has already been disclosed in prior art.

In this situation, the presence of a prior art species undermines the novelty of the generic claim, indicating it's not sufficiently innovative or non-obvious over what is already available. Therefore, this leads to the conclusion that the generic claim cannot be allowed if it is already anticipated by prior art.

In summary, the critical principle here is that for a generic claim to be substantively different and thus patentable, it must not be anticipated or rendered obvious by existing species in the prior art. This understanding is consistent with the requirements laid out in patent statutes and reinforced by patent law principles.