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Show 1891.] BRITISH CENTRAL AFRICA. 309 29. BREVICEPS VERRUCOSUS, Rapp ; Cat. Batr. Ecaud. p. 177. Lake Nyassa (Universities' Mission). Mr. E D G A R A. S M I T H offered the following remarks on the Molluscan Fauna of British Central Africa:- So far as I can ascertain, very little seems to be known of the Mollusca of this region, and it is only that part of the country near Lake Nvassa and the lake itself which have been partially investigated. Sir John Kirk was the first to collect in this district, and the specimens he obtained were described by Dr. Dohrn in the ' Proceedings' of this Society for 1865, and by Isaac Lea in the Proc. Acad. Nat. Sci. Philad. for 1864. Some years later Mr. F. A. Simons visited Nyassa and brought home a number of new forms from the lake, which I described in the ' Proceedings ' of this Society for 1877. Finally M . Victor Giraud, whilst travelling in the Lake region, also made collections of shells from Nyassa, which were reported upon by M . Bourguignat1 in 1889. These were obtained at the northern end of the lake, whilst those collected by Sir John Kirk and Mr. Simons were from the southern extremity. Judging from what we know of the Mollusca of that part of Africa which lies to the east and south of this district, I do not anticipate that many very remarkable forms will be discovered. Doubtless interesting intermediate links connecting some of the large species of Achatina may be met with, and a number of new species of other groups of Helicidae, besides a few forms of freshwater shells, will be found. It is to be hoped, however, that these conjectures may prove incorrect, and that future investigators will be rewarded by the discovery of many, not only new and interesting specific, but also generic forms. In Capello and Ivens's work 'De Angola a Contra-Costa,' a number of species collected by those travellers has been enumerated by A. Furtado. Although obtained to the south of British Territory, some of them have already been recorded from the Nyassa region ; and it is therefore probable that others, eventually, will also be found to range as far northward. In the following list none of the so-called species characterized by M. Bourguignat are quoted, because, in m y opinion, most of them, if not all, are merely varieties of those previously described. LIST OF T H E K N O W N SPECIES OF MOLLUSCA FROM LAKE NYASSA. 1. Limncea natalensis, Krauss. 2. Physa nyassana, Smith. 3. succinoides, Smith. 4. Physopsis africana, Krauss. 1 Bull. Soc. Mai. France, 1889, pp. 1-40. |