184 L1GUUS HEMIBULIMUS. 



always whitish. The development of the columellar fold ic indepen- 

 dent of the more or less slender form of the shell. The lip-edge is 

 white, only in young specimens, in which the lip had not attained its 

 full thickness, the external epidermis shows darkly through. Only 

 one of the lot is dextral. Four measure as follows: 



Length 68, diam. 30, length of aperture 30, width 16 mill. 



Length 56, diam. 32, length of aperture 27, width 17 mill. 



Length 56, diam. 29, length of aperture 25, width 14 mill. 



Length 53, diam. 32, length of aperture 25, width 16 mill. 



LIGUUS, sp. undet. PI. 35, fig. 18. 



A young shell before me differs from all other young specimens of 

 the group in being rounded at the periphery, without trace of a keel. 

 Whorls 6^ ; there is no articulated band in the middle of the whorls 

 of the spire, but one shows at the sutures, and a narrow continuous 

 purple-brown band bordered with cream-tint above, encircles the per- 

 iphery, becoming obsolete on the latter part of the whorl : another 

 narrow band is upon the base. As the young of regina, regalis and 

 incisus seem to be keeled, I am at a loss to tell where this shell 

 belongs. The locality, "Amazon," may not be reliable. 



Subgenus HEMIBULIMUS von Martens, 1885. 



Hemibulimus v. MART., Conchologische Mittheilungen, ii, p. 175. 



Shell rather fusiform, sculptured and dark colored ; aperture about 

 half the length of shell, the outer margin of peristome unexpanded 

 and obtuse, columellar margin deeply concave, the columella dis- 

 tinctly truncated at its base. Apex obtuse, the first whorl finely 

 wrinkled. 



Jaw composed of 13 imbricating plates, the median one reaching 

 to the lower margin. Radula with the central and inner two lateral 

 teeth on each side helicid in form, with long lanceolate mesocones 

 and slight rudiments of ectocones : the other teeth as in Orthalicince 

 generally. 



Type, Liguus excisus Martens = Achatina magnified, Pfr. 



The shell resembles Liguus in its Achatina-Vke columella, but 

 differs in the sculpture of the apex as well as of the rest of the shell, 

 and the dark coloration, characters assimilating it with Orthalicus. 

 The radula resembles Liguus virgineus and Orthalicus gallinasuhana 

 in the lanceolate cusps of the median teeth. Similarly shaped teeth 



