12 ZOOLOGISCHE MEDEDEELINGEN — DEEL IV. 



peristome retracted above, nearly straight lower on. Columella!* margin 

 slightly curved and reflected, a thin layer of enamel unites the margins 

 on the body-whorl. 



Alt. of largest specimen 31, diam. maj. 9' 2 ; apert. alt. 9 1 2 , lat, 

 nearly 6 mill. 



Sago-marsh, near the Kajo-bay. 



This species, of which several specimens have been collected, resem- 

 bles in many respects to M. dennisoniensis Brot, but the whorls are 

 slightly contracted above, the peristome has no sinus, nor are the whorls 

 angular at some distance below the suture; M. dennisoniensis has no 

 trace of ribs. It differs from 3/. costularis Lea, which is also costulate, 

 in very many respects, the ribs in that species ending at a distance from 

 the suture, it belongs to another section. 



7. Melania (Mdanoides) sentaniemis n. sp., PL I, fig. 7. 



Shell turreted, thin, dull, a few specimens with a light brown epider- 

 mis, but the majority quite eroded and whitish (one specimen with traces 

 of brown spots on the lirae). Spire slightly eroded, remaining whorls 

 till 6, very convex, rounded, separated by a linear suture. Sculpture 

 consisting of few, coarse, flattened spiral lirae, 5 or 6 on penultimate 

 whorl, about 10 on last one, several specimens with faint radial ribs, 

 extending more or less over the last whorls, but no sculpture is visible 

 on upper whorls (perhaps by erosion). Aperture ovate, acute above, rounded 

 below, only slightly compressed there, peristome thin, slightly curved 

 above, protracted below. Columellar margin nearly straight, flat, a rather 

 thick layer of enamel connects the margins on the body-whorl. Interior 

 of aperture colourless or with brown bands or irregularly mottled. 



Alt. of largest specimen 33, lat. 9; apert. alt. 8, lat. 5 mill. 



Lake Sentani, on the muddy shore, Jan. 14, 1911. 



The numerous specimens of this new species are very variable in 

 sculpture and colour of aperture, but they have all the same character, 

 and belong, no doubt, to the same species. They seem to belong to the 

 group of M. tuberculata Mull, but are quite different from the known 

 varieties, by their unusual convex whorls, with consequently deeply situated 

 suture and by the faint, but very coarse sculpture. 



8. Melania (Plotia) scabra Muller. 



Muller. Hist. Verm. Vol. II, 1774. p. 193. Brot. Martini-Chemn. Conch. Cab., 

 Ed. II, Mon. Melania, p. 266, PL 27, fig. 14, 15. v. Martens. Siiss- u. Brackw.- 

 Moll. d. Ind. Arch. p. 62. 



Zoutbron, June/ July 1910. 



The specimens resemble Brot's fig. 15a (1. c.) with spinous upper 



