2 12 



broad rim, by a large groove, with two intermediate rims, which are also crenulate; at the 

 proximal side of the broad rim runs a groove with a small rim therein. 



19. Natica helvacea Lamarck. 



Lamarck. An. s. vert. Ed. Desh. Vol. VIII, p. 637. 



Philippi. Martini-Chemii. Conch. Cab. Ed. II, Vol. II, Natica, p. 21, PI. 3, fig. i, 2; PL 8, 



fig. 5 (globosa). 

 Rkeve. Conch. Ic. Vol. IX, Natica, fig. 46 {globosa). 

 Tryon. Man. of Conch. Vol. VIII, p. 32, PI. 9, fig. 64. 



Stat. 133. Lirung, Salibabu-island. Up to 36 M. Mud and hard sand. 2 Spec. 

 Stat. 261. Elat, West coast of Great-Kei-island. 27 M. Mud. 2 Spec. 



The specimens are young. 



20. Natica crassa n. sp. PI. XIII, fig. 3. 



Stat. 58. Seba, Savu. Up to 27 M. Sand, i Spec. 



Shell small, subglobose, with blunt spire, thick, shining, with rather strong growth-striae, 

 strongest below the suture, and microscopic waved spirals. Whorls 4^/,, slightly convex, especially 

 the upper ones, which are separated by a conspicuous suture, which is shallower in the last 

 whorl; this suture strongly descends towards the aperture, and on this part the growth-striae 

 are very strong and crowded; just behind the aperture the shell is slightly contracted. Colour 

 white, with a large, irregular, yellowish-brown zone near the median part of last whorl, this 

 zone encloses irregular white spots. Aperture small, oval, with a blunt angle above; right 

 margin thick, curved, rounded below ; columellar margin nearly straight with a callous pad at 

 the upper part and a thick, subtriangular, porcellaneous deposit, forming in part the end of the 

 funiculum and covering the upper part of the umbilicus, which is narrow interiorly, but apparently 

 pervious; a deeply incised rather broad groove, separates the funiculum from the bodywhorl, 

 base of the columella joined to the thick, rounded basal margin of aperture by an angle which 

 produces a short tongue-shaped layer, just below the umbilical groove. Interior of aperture, 

 smooth, Avhite. 



Operculum wanting, but the columella has a slight groove, indicating the presence of a 

 calcareous operculum. 



Ah. 77,, lat. 87,,; apert. alt. 57,, lat. 3 Mill. 



This species may be recognized by its thick shell, by the strongly descending suture, 

 the strong striae near the aperture, which is unusually small. I know no nearly allied species. 



21. Natica supraoi")iata n. sp. PI. XIII, fig. 4. 



Stat. 274. 5°28'.2S., I34°S3'.9E. Near Aru-islands. 57 M. Sand and shells, stones. 2 Spec. 



Shell small, depressedly subglobose, with blunt spire; rather thick, smooth, whorls 370, 

 the nuclear one convex, the remaining nearly flat; sculpture consisting of very fine growth-striae, 

 more conspicuous near the suture and towards the aperture. Colour yellOwish-white, with a collar 



104 



