49 



sculpture, the whole shell has a smooth, shining appearance, with very fine lines of growth, the 

 last whorl having only a few spiral striae near the periphery. The vvhorls are slightly convex, 

 the last one is a little depressed and much enlarged, but has no keel; basal surface smooth, 

 with fine lines of growth and short, radiating striae round the umbilicus, which is large, pervious, 

 funnel-shaped, sculptured with lines of growth and about 9 spiral lirae. Aperture subcircular, 

 slightly angular above, compressed near the periphery, outer margin thin, columellar margin 

 sinuous, thickened, slightly reflected above, running without appreciable angle into the basal 

 margin. Interior of the aperture nacreous. 



Alt. 6, diam. maj. 10 1 /,, apert. alt. 3, lat. 4, diam. of umbilicus 3 Mill. 



This species varies only slightly in painting, the ziczac-lines being more or less numerous 

 and the bands more or less distinct, the blotches are often very distinct, but sometimes obvious 

 towards the aperture. 



5. zacalloides has been named on account of its very near relationship to S. zacalles Melv. 

 (Ann. Mag. Nat. Hist. Ser. 7, Vol. XII, 1903, p. 295, PI. 20, fig. 12), indeed it might be considered 

 with nearly the same right, as a variety of that species. Melvill had the kindness to send me his 

 only specimen for comparison, and at the first view it seemed to be identical. A close examination 

 however, has shown the following differences: the new species is larger (diam. maj. io 1 /, instead 

 of 9 Mill.) thicker, less conical, the last whorl is broader in proportion, its diameter being 3 /-, of 

 that of the whole shell, being only l j 3 in S. zacalles, consequently the aperture is less rounded. 

 The embryonic and postembryonic whorls are more depressed, they are provided with a more 

 obvious depression near the suture. The granules near the suture are less sharp, the concentric 

 striae shallower, on the penultimate whorl these striae extend in zacalles upwards to the beads, 

 in zacalloides there remains a smooth zone between the upper groove and the beads. The 

 colour is not reddish-brown (except in 2 specimens, probably on account of a rusty box), the 

 bands are more distant. The base in zacalles has conspicuous brown flames, in zacalloides the 

 design consists of a fine network, with a more or less conspicuous white zone and often a band 

 of darker blotches around the umbilicus. The radiating sulci round the umbilicus, are less 

 developed, especially towards the aperture, and are more crowded. The lirae in the umbilicus 

 are not beaded as in zacalles, but nearly smooth, the grooves less impressed. 



S. zacalloides, forms with zacalles Melv., lacvissima Martens, Minolia congener Sow. and 

 some other allied species, a group of smooth, coloured species of Solariella. According to the 

 radula it is not doubtful that they belong in part, and probably all to that genus. 



3. Solariella mutabilis n. sp. PI. III, fig. 7; PI. IX, fig. 8. 



Stat. 59. Western entrance, Samau-strait. 390 M. Coarse coralsand with small stones. 6 Spec. 

 Stat. 95. 5°43'.5 N., U9°4o'E. 522 M. Stony bottom. 4 Spec. 

 Stat. 159. o°59'. 1 S., I29°48'.8E. 411 M. Coarse sand. 1 Spec. 

 Stat. 253. 5°48'.2 S., I32°I3'E. 304 M. Grey clay, hard and crumbly. 1 Spec. 

 Stat. 260. 2,3 miles N. 63 VV. from N. point of Nusa Jaan, Kei-islands. 90 M. Sand, corals 

 and shells. 1 Spec. 



Shell trochiform, moderately strong, yellowish, with a rosé coloured zone on the upper 



part of the lower whorls, upper ones nacreous. Whorls 5 1 /., ; nucleus smooth, foliowed by a 



49 



SIBOGA-EXPEDITIE XI.IX 1 a. 7 



