Summary
A new species, Thalamita crosnieri, is described from Somalia. It belongs to the T. woodmasoni group and is distinguished by the shape of the front and of the gonopod. T. woodmasoni Alcock is restricted to Andamans, southern India and Ceylon while T. crosnieri is known from the eastern coast of Africa and Madagascar. T. cooperi Borradaile (from Somalia) and T. demani Nobili (from Aldabra), belonging to the same group of species, have also been illustrated.