l82 M. M. SCHEPMAN, LAND- AND FRESHWATER MOLLUSCA ETC. 



upwards to 3 white zones, but on account of the bad condition, it seems not désirable to 

 distinguish varieties. 



3. Neritina (Neritaea Pictae) ziczac Lamarck. 



Lamarck. An. s. vert. Ed. II, Vol. VIII, p. 570. (zigzag). 



v. Martens. Martini-Chemn. Conch. Cab., Ed. II, Neritina, p. 101, p. 280, PI. 10, fig. 21 



(coromandeliana). 

 Tapp. Canefri. Fauna Mal. New Guinea, p. 69. (ziczac Sow. non Lam.). 

 Tryon. Man. of Conch. Vol. X, p. 36, PL 10, fig. S8, (ziczac Sow.). 

 v. Martens. Sùss- u. Brackw.-Mollusken, p. 79. 

 New Guinea. Lorentz River, Sept. 5 — 12, 1909. 



The spécimen has in its upper whorls and a large part of last whorl, very narrow black 

 lines and a basai zone of much broader ones, agreeing rather well with the quoted figures. 

 Authors hâve much discussed the question if this species should be named ziczac Lam. or 

 Sow. or coromandeliana Sow., or even ramosa Meuschen, till v. Martens (Sùss- u. Brackw.- 

 Moll. p. 79) has declared to be convinced by the inspection of the type of LAMARCK, that 

 this species is the true ziczac of LamaRCK. 



4. Neritina (Neritodryas) simplex n. sp. PL VI, fig. 5. 



Shell globosely-turbinate, (often more or less eroded), whitish, with a yellowish epider- 

 mis, slightly orange-yellow towards the top; when it is not eroded, with very fine growth- 

 lines, irregularly intermingled with coarser ones and with a few short, spiral grooves. Whorls 

 about 3, the apical one slightly projected, the next more swollen, then much swollen in the 

 front view above the aperture, separated by a very deep and much descending suture. Aper- 

 ture moderately oblique, semi-elliptical, its basai margin regularly rounded, continuous on 

 the body-whorl as a rim, ending about halfway the columellar area, which is narrow, white, 

 with a slightly concave margin, with some partly very inconspicuous teeth, its posterior margin 

 is nearly straight, with a marked border, in the lower half of the posteror areal margin, a 

 narrow space is circumscribed by the rim, the area is rather dull, with very fine wrinkles. 



Operculum exteriorly light orange, with small granules, only visible under a very strong 

 lens, interiorly smooth, except along the columellar margin, vvhere a dull zone with a few 

 grooves, runs nearly parallel with the waved margin, claviform apophysis with many grooves, 

 its apical part multi-digitate, hollow below, the apical apophysis strong, connected to the 

 claviform one, orange, elegantly curved. 



Alt. 13, diam. maj. 12, apert. ait. (diagonally) 10, lat. 7 1 /., mill., of which about 2 for the area. 

 New Guinea. Alkmaar, Aug. 9, 1907. 



This species, which, by its operculum, evidently belongs to Neritodryas, is quite différent 

 by its colour, which is always the same in the numerous spécimens, in size it cornes nearest 

 to N. apiata RecL, but in shape it is considerably différent by its much swollen whorls. If 

 apiata be only a variety of dubia, as Trvon (Man. of Conch., Vol. X, p. 44) suggests, the 

 operculum should give another différence, as according to the description of V. MARTENS in 

 his Monograph, p. 138, the operculum of N. dnbia is totally différent ; unfortunately V. MARTENS 

 (1. c. p. 282) says that the operculum of N. apiata refers it to Neritodryas, but gives no 

 description of it. 



