The Helmet Shells. Cameo Shells 



longitudinal and spiral. Three rows of distant nodules occur 

 on the hump-backed body whorl. Brown blotches of varying 

 size ornament a yellow ground. The pale ground of the broad 

 columella is overlaid by dark brown streaks between the plications, 

 and toward the posterior end of the aperture a big patch of 

 bright chestnut occurs. A few large brown spots are disposed 

 around the margin of the outer lip. This is one of the pre- 

 ferred cameo shells; the white figure stands out clearly against 

 a black background. Length, 6 to 8 inches. 



Habitat. — North Carolina to West Indies. 



The Flame Helmet (C. flammea, Linn.) has a high, singly 

 ridged, conical spire, and is decorated with browns in flame-like 

 crescentic patterns, even on the face of the expanded columellar 

 lip. Big blackish spots follow the lip margins around. Strong knobs 

 range along the shoulder of the body whorl, with two fainter 

 and shorter parallel rows lower down. Length, 4 to 6 inches. 



Habitat. — West Indies. 



The Horned Helmet (C. cornuta, Linn.) is studded with 

 three spiral rows of tubercles, between which the surface is 

 finely honeycombed and has series of parallel rows of fine dots, 

 the area clouded with brown. Blotches of dark brown occur on 

 both lips and on the rows of knobs. The ground colour is creamy 

 white. One strong varix runs down behind the columellar lip. 



This is not only the giant of its family, reaching a foot in 

 length, but its distribution is over a belt that encircles the globe. 

 It inhabits the Indian Ocean, the Philippines, Japan and the West 

 Indies. In cameos it gives a white raised figure on an orange or 

 pink ground. 



CAMEO-CUTTING 



The black helmet is one of the best shells for cameo-cutting. 

 It has an "onyx ground," a dark coat under the pale outer layer, 

 so that the figure cut will stand out well. The inner lip of a 

 large shell should yield several brooches. Usually the back- 

 ground is claret-coloured, instead of black. 



The bull's mouth is red under a white outer coating. This 

 is known as a "sardonyx ground." C. cornuta cuts a white 

 figure on an orange ground. The queen conch (Strombus gigas) 

 is pink over a white ground. 



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