ZOOLOGISCHE MEDEDEELT N GEN — DEEL IV. 



I. LAND- AND FRESHWATER-MOLLUSCA. 



Class Gastropoda. 



Pulmonata. 



Suborder Geophila. 



A. MONOTREMATA. 



Fam. Zonitidae. 



Xesta Albers. 



1. Xesta citrina Linné. 



Linné. Syst. Nat. Ed. X, p. 771. v. Martens. Ostas. Landschn. p. 493. Reeve. 

 Conch. Ic. Helix, fig. 482, 485. Tapparone Canefri. Fauna Mai.. N. Guinea, p. 196. 

 Tryon. Man. of Conch., Ser. II, Vol. II, p. 73. 



Kaiserin-Augusta-river, on a tree, Sept. 18, 1910; one specimen 

 without exact locality. 



Both specimens are young; it is not to be made out to which variety 

 they belong. 



Eupleeta Semper. 



Eupleeta costeUifera n. sp., PI. I, fig. 3. 



Shell depressedly conoid, with rounded base, imperforate, dull above, 

 fulvous; sharply carinate at periphery. Whorls 5, slightly convex, separ- 

 ated by a very shallow suture, above which the whorls are depressed, 

 apex blunt, smooth ; sculpture of post-nuclear whorls consisting of rather 

 remote riblets, their interstices are finely striated, the base is nearly 

 smooth, but for faint growth-lines, stronger below the threadlike keel of 

 last whorl, which is pinched above and below. Aperture a little oblique, 

 securiform, margins distant, united by a thin callus on parietal wall. 

 Upper margin of peristome thin, basal margin thickened, rounded, run- 

 ning imperceptibly in the short columellar margin, which is reflected 

 above and quite closes the umbilical pit. 



Diam. maj. 16, alt. 8'/ 4 ; apert. alt. 5, lat. 7|/ 2 mill. 



Bougainville-mounts, June 1 — 2, 1910. 



Though this and the next species are located with some doubt in the 

 genus Eupleeta, I know no better place; amongst the species of that 

 genus at my disposal, I found some with the perforation closed or nearly 

 so. Amongst species from New Guinea, with about the same shape, I 

 found no one coming near to it as far as concerns the sculpture. 



2. Eupleeta imperforata n. sp. PI I, fig. 4. 

 Shell depressedly conoid, with rounded base, imperforate, dull above, 



