ARCHACHATINA. 117 



Group of A. knorri. 



Shell thin or fragile, not large, usually boldly marked, the 

 aperture lilac-white or bluish within, the external markings 

 showing through. Liberia to Kamerun. 



10. A. SIDERATA (Reeve). PL 25, fig. 24. 



Shell ovate, thin, olivaceous-yellow, profusely zigzag- 

 streaked and dotted with chestnut. Surface densely, finely 

 and distinctly granulose, the granulation becoming obsolete 

 below the periphery, where it is more glossy. Whorls 5, con- 

 vex, the apex large and obtuse. Aperture long-ovate, wide 

 and effuse below, acuminate above; interior lilac-tinted with 

 a pearly luster. Columella short, straightened, with a thin 

 narrow callous colored like the mouth. 



Length 55, diam. 32 mm. (Reeve's figure). 



Length 48, diam. 27, length aperture 30.5 mm. 



West Africa: Cape Palmas, Liberia, (Coll. A. N. S. P.). 



Achatina siderata REEVE, Conch. Icon, v, pi. 12, f. 38 

 (March, 1849). PFR., Monogr. iii, p. 486. ANCEY, J. de C. 

 1902, p. 280 (Cape Palmas). 



Somewhat related to A. knorrii and papyracea, but more 

 delicate, and with a different color-pattern. 



11. A. PAPYRACEA (Pfeiffer). PI. 44, fig. 1 ; pi. 23, figs. 17, 18. 



Shell ovate-oblong, thin, obsoletely decussate with longi- 

 tudinal and concentric striae, diaphanous, fulvous, obsoletely 

 marbled with chestnut. Spire conic, the apex obtuse; suture 

 margined. Whorls 5^/2, slightly convex, the last scarcely 

 longer than the spire. Columella nearly straight, reaching 

 nearly to the base of the aperture, obliquely truncate, orna- 

 mented with a purple line. Aperture oval, pearly within. 

 Length 66, diam. 30 mm.; aperture 35x19 mm. (Pfr.). 



West Africa: banks of the Nun river, one of the outlets 

 of the Niger (Cuming coll.). 



Achatina papyracea PFR., Proc. Zool. Soc. 1845, p. 74; 

 Monogr. ii, p, 254; and ? Conchyl. Cab. pi. 28, f. 8, 9. 

 REEVE, Conch. Icon, v, pi. 2, f. 6. 



Fig. 1 of pi. 44 represents what I take to be the type 



