80 SUBULINA, WEST AFRICA. 



types, the length being 17, diam. 4, aperture 3.9 mm., whorls 

 over 9; the whorls are a trifle more convex than in Prince 

 Island specimens. The smooth embryonic shell has sub- 

 sutural erenulation as in 8. striatella. The color is a slightly 

 brownish olivaceous yellow. 



7. S. VIVIPARA (Sowerby). PL 11, figs. 94, 95. 



"The shell is commonly about an inch long, consisting of 

 a/bout 9 volutions, the apex being blunt and rounded, the 

 volutions longitudinally striated and the base smooth; the 

 whole nearly white, semitransparent, and covered with a 

 thin olivaceous horny epidermis. 



"Three or four fully developed young shells may generally 

 be found upon breaking up a full-grown shell, occupying 

 commonly a great portion of the second, third and fourth 

 volutions from the base. The young ones consist of three 

 volutions before they quit the parent" (Sowerby}. Local- 

 ity not given. 



Achatina vivipara SOWERBY, The Malacological and Con- 

 chological Magazine, part 1, 1838, p. 27. PFR., Symbolae iii, 

 p. 91 ; and in Philippi, Abbild. u. Beschreib. neuer Conchyl. 

 ii, p. 216, pi. 1, f. 5 (specimen received from Sowerby) ; 

 Monogr. ii, p. 264; Conchyl. Cab. p. 340, pi. 37, f. 15, 16. 

 REEVE, Conch. Icon, v, pi. 16, f . 70. 



Pfeiffer describes a specimen received from Sowerby as fol- 

 lows: "Shell turrited-subulate, rather solid, longitudinally 

 closely rib-striate, rather shining, waxy- whitish. Spire elon- 

 gate,, the apex rather obtuse, whorls 10, convex, the last one- 

 fourth the total length, angulate. Columella slightly arcu- 

 ate, not reaching the base, obliquely truncate. Aperture 

 semioval, the peristome thin. Length 20, diam. 5.5, aperture 

 5x3 mm. ' ' His figures of this shell are copied on my plate. 



This species differs from S. angustior in the following fea- 

 tures: "It is a stronger shell, less slender, and has usually a 

 whorl less in the same length. The rib-striae are nearly 

 parallel to the axis throughout, and are a little stronger. 

 The whorls are less 'convex, the last more acutely angular. 

 The aperture is wider, and the columella far more bluntly 



