The Top Shells and Dolphin Shells 



ones. The apical coils have nodules; the outer ones are smooth. 

 The aperture is oblique; the columella has a spiral fold above and 

 a strong tooth below. The umbilicus is shallow. These shells 

 are from four to five inches in diameter and a trifle less in height. 



Bracelets of pearl cut from these shells are highly prized 

 by the South Sea Island \yomen. If solid cross-sections cannot 

 be had, two or three piecfes are fastened together with string. 

 Five or six are worn on one arm. 



Habitat. — Indian Ocean and Australian waters. 



The Acute-angled Top Shell (T. acutangulus, Chemn.) 

 of the same regions is a smaller shell; its apex is a very sharp 

 point, and its white sides are variously streaked with bright red. 

 Rows of small beads adorn the whorls. The shells average two 

 to three inches in height and somewhat less in diameter. 



Habitat. — Eastern Seas. 



The Toothed Top Shell (T. dentatus, Forsk.) has a heavy 

 tall spire, its coils (about twelve) armed with large remotely set 

 knobs, which stand out perpendicular to the surface. The 

 colour is pale, with faint and fine markings of red. There is a 

 broad band of green or blue surrounding the axis. This species 

 is about three inches high and two and a half inches in diameter. 



Habitat. — Red Sea, Persian Gulf. 



The Common Top Shell of the Mediterranean coasts (7. 

 ^i^yphinus, Linn.) is regularly pyramidal, solid, glossy, with a 

 strong rounded ridge spotted with brown at the base of each 

 whorl. The ground colour ranges from brown to lilac, streaked 

 in zigzag bands with brown. A full-grown specimen has a dozen 

 coils. The animal is as vividly coloured as the shell. The promi- 

 nent head has a two-lobed flap between the long tentacles. The 

 black eyes are on short stalks. Four pairs of cirrhi are thrust 

 out sidewise from the mantle, as the creature crawls along the 

 sea bottom, carrying the shell erect on its back, and the oper- 

 culum lying behind it on the extended foot. From low water 

 mark to many fathoms depth this mollusk thrives, its food the 

 seaweed. The shell measures somewhat over an inch in height 

 and diameter of base. The lining is beautifully pearly. 



A variety, conuloides, Lam., is found on the Atlantic coast 

 of Europe. It shows great variability from almost smooth 

 whorls to strong spiral ribbing, including all intermediate forms. 

 In colouring there is little variation from the type species. The 



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