188 Transactions of the Royal Society of South Africa. 



Melampus kusteri (Krs.) var. oblongus Kiist., 1844. 



1844. Auricula Jciisteri Krs., var. oblonga Kiist., Conch. Cab., p. 34. D. 



Hab. L. Marques. Estuary of Nkomati River, Rikatla (Jmiod). 



The foregoing names are correctly applied to the three forms of Melampus 

 from the above locality ; but whether the names are good in themselves, 

 or should be merged in the synonymy of older ones, is open to question. 



While nearly every species of this genus seems to vary so greatly that 

 each combines the distinctive attributes of others, certain forms which 

 appear almost, if not absolutely, identical in all conchological characters 

 occur throughout nearly the whole expanse of the Pacific and Indian 

 Oceans, so that names originally bestowed on Philippine species have been 

 applied to South African, and vice versa. 



Whether such a distribution is possible can only be determined by the 

 anatomist, but it seems so improbable that I prefer to retain, for the 

 present, the names originally created for African species. 



Subfamily AURICULINAE. 

 Genus Auriculastra von Martens, 1880. 

 Auriculastra acuta. Conn., 1922. 

 (Plate IV, fig. 29.) 

 1922. Auriculastra acuta Conn., A.M.N.H. x, p. 121. D. 

 Hab. L. Marques. Estuary of Nkomati River (Junod). 

 Type in Kimberley Museum. 



Auriculastra acuta is found in company with the three Melampi in the 

 mangrove region in the estuary of the Nkomati River, which can only be 

 approached on foot at low tide, when the mud is exposed and its surface 

 covered by thousands of crabs. Immature examples of all four species were 

 collected alive on the mud under rotten stems, but larger shells were only 

 found in dead condition on its seaward boundary, where they appeared to 

 have been left by the tide. 



The type measures 17-8 X 8-0 mm., and three other examples 17-6 X 7-2, 

 16-1 X 6-2, and 8-8 X 3-8 mm. respectively. 



In all stages of growth the spire of this species is comparatively longer 

 than that of any other African member of the genus. 



Family LIMNAEIDAE. 



Genus Limnaea Lam., 1799. 



Limnaea natalensis Krs., 1848. 



1848. Limnaeus natalensis Krs., Siidafr. Moll., p. 85, pi. 5, fig. 15. D.F. 

 Hab. Mozambique. R. Quilimane (Peters). 



