6-Month Extension of Final Determination on the Proposed Endangered Status for Texas Hornshell (Popenaias popeii); Proposed rule; reopening of the comment period.

We, the U.S. Fish and Wildlife Service (Service), announce a 6-month extension of the final determination of whether to add the Texas hornshell (Popenaias popeii), a freshwater mussel species from New Mexico, Texas, and Mexico, to the List of Endangered and Threatened Wildlife. We are also reopening the comment period on the proposed rule to list the species, for an additional 30 days. We are taking this action to extend the final determination based on substantial disagreement regarding the status of Texas hornshell in Mexico. We will submit a final listing determination to the Federal Register on or before February 10, 2018.