160 PSEUDOGLESSULA. 



P. duseni d'AiLLY, Bihang etc., p. 107, pi. 5, f. 8-10. 



By its form and size this little species approaches P. fus- 

 cidula (Mor.), but it is of a darker brown color, verging into 

 reddish instead of greenish; the shell is more solid, and the 

 sculpture more emphatic except at the summit where it is 

 the same in the two species. The ribs are more spaced, and 

 less arcuate and oblique. The surface wants the silky ap- 

 pearance of the other species; and the ribs are darker than 

 the rest of the shell, while in fuscidula they are the same color. 

 The entire form is more slender, and in specimens of the 

 same length, P. duseni has more whorls ; the sculpture of the 

 base is weaker, and its color paler. 



3. P. FUSCIDULA (Morelet). PI. 61, fig. 98. 



Shell oblong- tur rite, club-shaped, the apex rather acute; 

 thin, obliquely ribbed, crystalline under a brown- greenish 

 cuticle. Whorls 7, a little convex, the last angulated below, 

 scarcely one-third the total length. Columella arcuate, obli- 

 quely truncate, nearly reaching to the base. Aperture semi- 

 oval, colored within like the outside; peristome simple, acute, 

 unexpanded. Length 8, diam. 3 mm. (Morel.). 



West Africa: Gaboon coast (Morel.) ; Cameroons at 

 Ekundu-Etitti, Boangola, Bonge and Itoki (Dusen, Sjostedt). 



Achatina fuscidula MORELET, Series Conchyliologiques i, 

 p. 26, pi. 1, f. 9 (1858). PFR., Monogr. vi, p. 238.Stenogyra 

 (Subulina) fuscidula PFR., Nomenclator Hel. Viv. p. 328 

 (1881). Pseudoglessula fuscidula d'AiLLY, Bihang, p. 106. 



"All the characters of this pretty species assign it a posi- 

 tion among the Pseudoglessulae. The embryonic whorls are 

 sculptured with regular ribs more widely spaced (especially 

 on the first two whorls) and less oblique than those of the rest 

 of the shell, where they are irregular and obliquely arcuate. 

 The last whorl has a thread-like angle" (d'Ailly). 



According to d'Ailly the type was not fully adult. The 

 largest Cameroon shells measure 11.5 mm. long, 3 wide, with 

 9% whorls. It is found not only on dead leaves but on 

 plants as well, always solitary, never in abundance as the 

 Subulinas are. 



