236 PSEUDOTROCHUS. 



extending to the mouth, which is oval; columellar margin 

 angularly excavated, the columella truncate, and yet joined 

 to the right margin, which is without flange and not acute. 

 A distinct sinus at the junction of the right margin with 

 the last whorl. Coloration in two descending bands on the 

 last whorl, the upper one quite deep brown-violaceous, inter- 

 rupted with fawn stripes; the lower of a yellowish white 

 tinted with blue, and as though picked out with undulating, 

 transverse lines; the second whorl without evident bands, 

 and striped with reddish violet. The last 5 whorls of a dirty 

 white, with some spaced yellowish bands. Inside of the 

 mouth of a deep fawn tint. This shell is remarkable for its 

 mamillate spire, not occurring in any other species of Acha- 

 tina, and for its Bulimus-like aspect. The individual exam- 

 ined was covered with cicatrices. Length 7, width 5 decim. 

 (Joannis). 



West Africa: Prince's Isle, Gulf of Guinea (Joannis). 



Achatina saulcydi JOANNIS, Guerin's Mag. de Zool., 1834, 

 cl. v, pi. 50. DESK, in Lam., An. s. Vert., viii, p. 305. PFR., 

 Monogr., ii, 243; iii, 478. Perideris s., PFR., Monogr., iv, 

 596; vi, 203. 



Joannis' figure was reversed, probably by an engraver's 

 error, as most authors have thought, though no intimation of 

 this is contained in the original account. Fig. 20 is a copy 

 of the original figure, modified only in being made dextral. 

 Reeve and Deshayes have also given copies of Joannis' fig- 

 ure, as the species is one of great rarity in collections. The 

 original description of the coloration agrees but poorly with 

 the figure, and Joannis' measurements also show careless- 

 ness, at least. 



19a. Var. NORMALIS (Pilsbry). PL 11, figs. 21, 22. 



Shell resembling Achatina saulcydi Joannis in general col- 

 oration, being white streaked with livid purple, with some 

 bluish suffusion, the penultimate whorl whitish with livid 

 red flames. Whorls about 7%, the earlier 3 forming a mamil- 

 lar mucro, higher and more distinctly differentiated than in 

 saulcydi; following whorls forming a more tapering cone 



