110 ARCHACHATINA. 



Length 100, diam. 59, length aperture 61 mm. 



Length 127, diam. 74, length aperture 78 mm. 



Length 125, diam. 79, length aperture 84 mm. 



West Africa: Guinea (Swainson) ; banks of the Niger. 

 (Morelet). Gabun and Dahomey (coll. A. N. S. P.). Kame- 

 run at Massaka, Mekango, Etome and N'dian (Duzen) ; 

 Victoria (Buchholz) ; Barombi, Bula (Preuss). Loango 

 coast at the mouth of the Quillu, northward from Loango 

 (Mechow). 



Achatina marginata SWAINS., Zoological Illustrations i, 

 pi. 30 (1820-21) ; Malacology p. 170, f. 23. PFR., Conchyl. 

 Cab. Achatina, p. 328, pi. 29, f . 1 ; Monogr. ii, p. 249 ; vi, 212. 

 MORELET, Voy. Welwitch, p. 65, no. 23; Ser. Conch, i, p. 19. 

 (Gabon). SEMPER, Reisen im Archip. Phil., Landmoll, p. 

 144 (anatomy). v. MART, in Albers, Die Hel. 1860, p. 201, 

 with var. gracilior; Monatsber. Akad. Berlin 1876, p. 257, pi. 

 2, f. 1 (living animal) ; Jahrb. d. D. Malak. Ges. 1882. p. 245; 

 Sitzungsber. Ges. naturf. Freunde Berlin 1891, p. 30, 33. 

 d'AiLLY, Bihaiig etc. p. 61, 69 (fig. of teeth). Helix mar- 

 ginata RANG, Ann. Sci. Nat. xxiv, p. 33. Helix amphora 

 FER., Prodr. p. 50, no. 352 (nude name), and p. 70, where 

 marginata Sw. is given as a variety. 



This abundant species is distinguished by its expanded lip, 

 large white mouth, relatively smooth surface and obtuse sum- 

 mit. The type of Swainson seems to have been a small ex- 

 ample, his figure measuring 104 mm. long. It is white- 

 mouthed, and rather narrowly striped. 



Both size and markings vary widely. The largest shell 

 before me measures 140 mm. long. If the large form proves 

 to be varietally separable, it should be called var. amphora 

 (pi. 25, f. 26). Fig. 22 of pi. 24 represents a young shell 

 of four whorls, natural size. 



D'Ailly remarks that there are two forms in the Kamerun. 

 The larger, which measures up to 140 mm. long and about 70 

 wide, is characterized by spiral striation on the upper whorls. 

 The color is brown flamed, here and there violet, and broken 

 into dots. The summit and columella generally lack rose 

 color, the aperture is bell shaped, and the basal margin de- 

 scends deeply below the columella. The smaller variety is 



