title: Description of two new species of Rissoella Gray, 1847 (Mollusca, Gastropoda, Heterobranchia) from Venezuela, with a key to the Caribbean species known for the genus.
abstract: Two new species of the genus Rissoella Gray, 1847 are described from Venezuela, one from the National Park Morrocoy, Rissoella morrocoyensissp. n. and the other from the Wildlife Refuge Isla de Aves, Rissoella venezolanicolasp. n.Rissoella morrocoyensissp. n. has a deep umbilicus (partly closed), preumbilical cord, black head, hypobranchial gland marked by a pale yellow boomerang-shaped ribbon and it lives on the leaves of the seagrass Thalassia testudinum Banks & König, 1805. Rissoella venezolanicolasp. n. has an angled preumbilical cord which extends to the columella delimiting a trapezoid, a hypobranchial gland marked by a yellow quaver-shaped ribbon and protoconch with fuchsia highlights. It lives on the brown alga Dictyota spp. The records of Rissoella in the Caribbean are revised and illustrations, a comparative table and a key to the Caribbean species known for the genus are provided.
authors: Department of Oceanology and Coastal Sciences, Venezuelan Institute for Scientific Research, Carretera Panamericana km 11, Altos de Pipe, Miranda, Venezuela.
authors: Manuel
authors: M
authors: Caballer
authors: Jesus
authors: J
authors: Ortea
authors: Samuel
authors: S
authors: Narciso