126 ACHATJNA, WEST AFRICA. 



that on the back of the last whorl there appear to be whitish 

 lines so disposed on an almost black-chestnut ground as to 

 produce an elegant and characteristic delta design. The 

 aperture is ovoid, bluish-white, glossy inside and showing 

 the external pattern through. Right margin simple and 

 sharp ; columella very strongly arcuate ; on the parietal wall 

 a mere trace of callous. Length 33, diam. 12.5, aperture 

 13x7 MIDI. (Furlad-o, Journ. de Conchyl., 1886, p. 145, pi. 

 6, f. 2). 



22. A. ZEBRIOLATA Morelet. PI. 6, figs. 13, 14. 



Shell ovate or elongate, obsoletely and irregularly striate, 

 a little glossy, whitish-fulvous or gray, painted with scarlet, 

 sinuous, longitudinal or oblique stripes. Spire elongate, the 

 apex rather obtuse, the suture impressed, in the last two 

 whorls generally margined. Whorls 8 to 8y 2 , & little convex, 

 the last three-sevenths the total length. Columella arcuate, 

 slightly truncate, nearly reaching the base. Aperture ellip- 

 tical, milk-white within, showing the bands through; peri- 

 stome acute and unexpanded. Length 35, diam. 15, aperture 

 14i/ 2 x 9 1/, mm- (Morel). 



West Africa: Golungo-Alto, on aquatic plants on the Rio 

 Quiapose, not far from Sange, Angola (Dr. Welwitsch). 

 Malange on the Quanza (Mechow) ; Malash on the Kassai 

 (Buchner) . 



Ackatina zebriolata MOREL., Journ. de Conchyl., xiv, 1866, 

 p. 158; Voy. Welwitsch, p. 72, pi. 3, f. 1. PFR., Monogr., 

 vi, p. 219. v. MART., Jahrb. d. D. Malak. Ges., ix, 246. 



23. A. POLYCHROA Morelet. PL 5, figs. 2, 3, 4, 5. 



Shell oblong-conic or fusiform, rather solid, plicatulate- 

 striate, and somewhat decussated in places by lightly- 

 impressed spiral lines. Whitish or fulvous, variously 

 painted with wide chestnut flame-like or zigzag stripes, 

 confluent at the base, and spots of the same color. 

 Spire long, the apex rather acute; suture submargined. 

 Whorls 9, a little convex, arcuately plicatulate-ribbed be- 

 low the sutures, the last whorl a little more than two- 



