QUICKIA ALDABRAENSIS (MOLLUSCA, GASTROPODA: PULMONATA, SUCCINEIDAE), A NEW SPECIES OF LAND SNAIL FROM ALDABRA ATOLL, WESTERN INDIAN OCEAN By C. M. PATTERSON INTRODUCTION THE Succineidae, a rather diverse land snail family, currently includes 12 recent genera (Patterson, 1971, I973a). Succinea, Oxyloma and Catinella have received the most attention by researchers, while representatives of the remaining genera have scarcely been studied. Quickia is distinguished from other succineids by the position of the right tentacular assembly (situated entirely to the inside of the terminal genitalia) combined with the lack of a penial sheath and penial appendix. Some unique features of Quickia were first reported by H. E. Quick (1936), but the genus was not named formally until 14 years later by Odhner (1950). The distribution of Quickia given by Odhner was '. . . from Liberia to the Cameroons and Gabon, on Prince Island and San Thome to East Africa (Zanzibar and Mauritius, as well as, according to Madge, 1938, Rodriguez, Reunion and the Seychelles).' Subsequently, Quickia received no further attention until the reproductive anatomy and chromo-some number of Q. spurca (Gould) was described (Patterson, 1968). Following that, the existence of Quickia in India was reported in a morphological and cytological study of two Indian species (Patterson, 1970). In addition to its unique genital morphology, Quickia is of cytological interest because all five species studied have 25 pairs of chromosomes, the highest number known in the Succineidae. The objectives of this report are (i) to describe a new species of Quickia from the Indian Ocean island (atoll) of Aldabra and to record its chromosome number ; (2) to briefly review the distribution of Quickia and (3) to discuss some aspects of the biology and systematics of the genus. MATERIALS AND METHODS Several living specimens of Quickia aldabraensis were forwarded to me by C. A. Wright of the British Museum (Natural History) in January 1968. Eleven successive generations were produced during the following two years. Methods of laboratory culture are described in Patterson (1971, 1972). The following locality data and habitat description were provided by J. F. Peake (personal communication) also of the British Museum (Natural History). The specimens were collected by J. D. Taylor while participating in the Royal Society Expedition (1967-68) to Aldabra Atoll. The snails were found on the platin area at the eastern end of South Island (Fig. i) where the surface limestone is impervious to rain water. They were observed Bull. By. Mus. nat. Hist. (Zool.) 28, 5 Issued 17 September, 1975
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