CHAPTER XXVII: THE SUN-DIAL SHELLS 



Family Solariid^ 



Shell spiral, depressed, conical, top-shaped or flat; aper- 

 ture angular; lip and columella simple; umbilicus wide, deep, 

 usually with scalloped margin; lining not pearly; operculum 

 spiral. Animal with large oval foot, notched in front; the 

 eyes on the bases of the stout tentacles; radula with spiny 

 teeth; jaws present. 



Genus SOLARIUM, Lam. 



Shell a regular, depressed cone, with an angular edge; sculp- 

 ture elaborate, close, strong, crossing the spiral ridges forming 

 patterns in colours. World-wide genus in warm seas. 



The Granulated Sun-dial Shell (5. granulatum, Lam.) 

 found from North Carolina to the West Indies, and from Panama 

 to Lower California, is finely checked by the crossing of spiral and 

 radiating ridges, so as to have raised granules all over its upper 

 surface. The flat base has them enlarged to nodules as it closes 

 in to the narrow umbilicus. The surface is china-like, the whorls 

 purplish, the upper edges white, and decorated with large brown 

 dots in a single row. The largest specimens are about two inches 

 across. 



S, verrucosum, Phil., is one to two inches across, with 

 creamy yellow ground marked with numerous short streaks of 

 brown. The umbilicus is narrow and has prominent teeth. 

 This species may be a form of S. granulatum. West Indies. 



The Oriental Sun-dial Shell (S. perspedivum, Linn.) is a 

 depressed cone with angled margin and flat base. Its whorls 

 have a spiral depression below the sutures; this also is seen on 

 the basal coils, and in the broad umbilicus. Narrow ridges on 

 each side of the depression are marked with brown spots. The 

 ground colour is yellowish brown or ashy purple. Cloudy oblique 

 bands cross the median surface of the whorls. Diameter, 2 to 5 

 inches. Indian Ocean, Pacific Ocean, China to Australia. 



156 



