New species of Gradiconus and Kohniconus from the western Atlantic (Gastropoda: Conoidea: Conidae, Conilithidae).

Two new species are described. One is a new species of Gradiconus, G. ostrinus n. sp. The species has a small shell (less than 35 mm) with spiral rows of dark purple-brown spots over a light purple ground color. The ground color distinguishes it from all other western Atlantic Gradiconus. The species is also narrower bodied that are species included in the Gradiconus gibsonsmithorum species complex, which is defined herein. The second species is a new species of Kohniconus, K janowskyae n. sp. The species has a moderate sized shell (less than 40 mm) with dark brown to tan colored makings that are organized into longitudinal groupings over a white ground color on the teleoconch whorls. This species can be confused with Conasprelloides vi lepinii (Fischer & Bernardi, 1857). However, the latter has spirals on the teleoconch sutural ramps. Such spirals are absent in K. janowskyae n. sp. and other species of Kohniconus. The new species is the western Atlantic cognate of K. arcuatus (Broderip & Sowerbyl, 1829) from the Eastern Pacific.