. Annals of the South African Museum = Annale van die Suid-Afrikaanse Museum. Natural history. A Monographic Survey of South African Non-marine Mollusca. Ill Section Afrorhytida Shell with ribs on upper surface becoming weaker on last whorl; umbilicus narrow in immature shells, though sometimes expanding later in depressed examples. Cusps of inner laterals with narrow, or no lateral flanges; marginals narrower than in Hyperrhytida, about 12-22 on each side. Natalina knysnaensis (Pfr.). (Text-fig. 9.) Kef. List No. 124. 1845. Helix knysnaensis Pfr., , p. 131. D. 1934. Natalina knysna
. Annals of the South African Museum = Annale van die Suid-Afrikaanse Museum. Natural history. A Monographic Survey of South African Non-marine Mollusca. Ill Section Afrorhytida Shell with ribs on upper surface becoming weaker on last whorl; umbilicus narrow in immature shells, though sometimes expanding later in depressed examples. Cusps of inner laterals with narrow, or no lateral flanges; marginals narrower than in Hyperrhytida, about 12-22 on each side. Natalina knysnaensis (Pfr.). (Text-fig. 9.) Kef. List No. 124. 1845. Helix knysnaensis Pfr., , p. 131. D. 1934. Natalina knysnaensis Pfr., Watson, Proc. Mai. Soc, xxi, p. 156. N. Shell of fair size, subglobose, umbilicate, thin, silky, glossy, semi-transparent, corneous, dark to yellow brown, the type being of the former shade. Spire moderately exserted, apex bluntly rounded. Whorls 4, convex, rounded at the periphery, rather rapidly increasing, first 1£ smoothly malleate, but considerably worn in all specimens that I have been able to examine, remainder sculptured above with close, regular, nearly straight transverse costulae which become much weaker beneath, and both the base and upper surface of the last whorl show a certain amount of extremely faint microscopic spiral striation; suture simple, rather deep. Aperture f-lunate, descending a little at base, peristome white, glossy, almost imperceptibly thickened, labrum nearly straight in profile, receding gradually to the base, columella short, margin triangularly reflexed, overhanging a quarter of the umbilicus. Diam. maj. (type) 24-2, min. 20-7; alt. 17-4; apert. alt. 13-4, lat. 11-3 mm. Hab. CAPE PROVINCE. Knysna (type, coll. Cuming); Port Elizabeth (Crawford; Far- quhar); Somerset East (Miss Bowker); Enon (Hartvig). Type in British Museum. The radula figured is in the Gwatkin collection, labelled "Cape"; it measures 14-5 mm. in length and about 2 in breadth, marginals not included. There are 79 complete rows of teeth with formula 16 + 1
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectnaturalhistory, booky
