﻿Vol. 66.~] NON-MARINE MOLLUSCA, ETC. FROM NTASALAND. 241 



to include in it Erauenfeld's capillata, robertsoni, and Jeffrey si, all 

 of which are found in the lake at the present day. Mr. Edgar 

 Smith, who has for long studied the mollusca of African fresh- 

 waters, agrees with me in thinking that if examples of capillata, 

 at least, were mixed with a series of unicolor, it would be almost 

 impossible to separate them. In this connexion, it is interesting 

 to note that Dr. E. von Martens regards jeffreysi as a variety of 

 unicolor, and robertsoni as closely allied. 



Localities. — The isolated shells were obtained at an elevation 

 of 20 feet above the present lake-level at Chiwondo ; the marl-casts 

 came from about 3 miles west of Chiwondo, at an elevation of some 

 350 feet ; while the limestone-casts were collected at Chisali, some 

 15 miles west of the lake-margin, at a height of about 400 feet. 



Distribution. — The species was originally described from the 

 canal at Alexandria, and has since been recorded from most African 

 freshwaters. Jickeli mentioned its occurrence in a subfossil state 

 in the neighbourhood of the Libyan Desert, and in later years 

 Dr. Blanckenhorn recognized it in the Quaternary deposits of the 

 Nile Valley near Wadi Haifa. 



Genus Lanistes, Monti ort. 



' Conchyliologie Systernatique ' 1810, vol. ii, p. 123^ 

 Type = Cyclostoma carinata, Olivier. 



Lanistes solid its, E. A. Smith. (PL XYI1I, figs. 6 & 7.) 



Lanistes solidus, E. A. Smith, Proc. Zool. Soc. London (1877) 1878, p 716 & 

 pi. lxxiv, fig. 10. 



This species is represented by large (66 x 62 millimetres) and 

 medium-sized (40 X 38 mm.) specimens in a good state of preserva- 

 tion, with remnants of the periostracum sometimes preserved. 



Locality. — Chiwondo: at an elevation of about 20 feet above 

 present lake-level. 



Distribution. — Lake Nyasa. 



Terrestrial Forms. 



Genus Achatina, Lamarck. 



Mem. Soc. Hist. Nat. Paris, 1799, p. 75. 

 Type = Bulla achatina, Linn. 



Achatina craveni, E. A. Smith. 



Achatina Tcirlcii, E. A. Smith, Ann. & Mag. Nat. Hist. ser. 5, vol. vi (1880) 



p. 428. 

 Achatina craven?, E. A. Smith, Proc. Zool. Soc. London, 1881, p. 283 & pi. xxxiii 



fig. 11 ; ibid. 1899, p. 590 & pi. xxxv, figs. 1-2. 



Localities. — Chiwondo ; Masiunjuti. 



Distribution.— In regions between Lake jSTyasa and the East 

 Coast of Africa. 



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