PSKlIDOSTROMniS. 15 



Kioner, who figures this spocios ns Biiec. viUatinn, Limi., coii- 

 roiinds with it B. vielanoide-ff, :i sliell from the opposite eojist of 

 Africa, and quite distinct, judging from the specimens before me. 

 Lamarck considered it a Terehra, a genus to wliich this shell is 

 closely assimilated l\y its usually very nari'ow form, i)olislu'd 

 surface and sculpture. 



B. POLTTA, Lam. PI. ^^, figs. 88, 89. 



Cream-color, yellowish brown or livid olive, with frequently a 



very indistinct darker band near the suture; whorls of the ai)ex 



plicate, rest smooth and polished. Length, 1-1-25 inches. 



Senegal. 

 B. vUrea, Reeve (fig. 89), is synonymous. 



B. KuRRACHENSis, Angas. PI. 6, fig. 90. 



White, tinged with rose-color on the upper whorls. 

 Length, 1*75 inches. 



Kurrachi, Scinde, i^. W. India. 

 Only the type specimen known. 



B. viTTATA, Linn. PI. 6, figs. 81, 92. 



Yellowish or lilac-white, or bluish or brown; sometimes the 

 spire is clouded bluish whilst the rest of the shell is light colored. 

 Sutural plications defined by an incised revolving line and some- 

 times cut in two by another line. Length, 1'5-1*75 inches. 



Ceylon; Zanzibar. 



B. livida, Reeve (fig. 92), is only one of the many slight vari- 

 ations which can be readily traced to the typical form. This 

 species occasionally^ develops a varix on the outer lip, and speci- 

 mens are before me in which a former varix is persistent. 



B. Taheitensis, Gmelin. PI. 6, fig. 93. 



Spirally ridged, ridges finely granose, two or three ridges next 

 the suture more distant than the rest; yellowish, maculate with 

 orange-brown, interior of aperture brown stained. 



Length, I'lS inches. 



Taheiti. 



A very rare species, and the only one having its pattern of 

 sculpture. The figure in Chemnitz is evidentl}^ poorly drawn, 

 and there can be no doubt that the British Museum specimen, 

 figured by Reeve, is a better representation of the species, as it 

 more nearly approaches a specimen now before me. 



