Comitas declivis is an extinct species of sea snail, a marine gastropod mollusc in the family Pseudomelatomidae. Fossils of the species date to the Waipipian stage (3.70 million years ago) of the late Pliocene in New Zealand, and are known to occur at Waihi Beach near HÃÂwera, South Taranaki. The species lived in deep waters off the coast of New Zealand.
In the original description, Powell described the species as follows:
The holotype of the species has a height of and a diameter of . Similar in appearance to C. bilix, the species can be identified due to being more elongated, and having less prominent basal cords.
The species was first described by A. W. B. Powell in 1931. The holotype was collected in January 1931 by Powell from near the mouth of Waihi Stream, HÃÂwera, South Taranaki. It is held in the collections of Auckland War Memorial Museum.
C. declivis was a species that lived in deep waters.
This extinct marine species occurs in late Pliocene Waipipian stage fossils in New Zealand, including the Tangahoe Formation.