On the two 'forms' of Dotilla intermedia De Man, 1888 (Crustacea: Brachyura: Dotillidae) from the Bay of Bengal, India, with description of a new species.

Two distinct morphotypes of sand bubbler crab (Dotillidae) from eastern India were assigned to Dotilla intermedia De Man, 1888, by British carcinologist, Stanley Kemp in 1919, due to similarities in the areolation of the carapace and the occurrence of these two forms in the same locality. Kemp, however, also illustrated the differences in the morphology of the male thoracic sternums, chelae, and first gonopods and, accordingly, divided D. intermedia into two subcategories which he called the "high form" and the "low form". The recent designation of a lectotype for D. intermedia, which corresponds with Kemp's "high form", makes it possible to recognize the "low form" as a distinct and new species, D. fraternalis n. sp., which is described here. Furthermore, Kemp's synonymization of Dotilla clepsydrodactylus Alcock, 1900, under Dotilla intermedia is affirmed here after examination of the surviving syntypes. A lectotype is selected to stabilize the taxonomy of this species.