The Turban Shells and Star Shells 



T. iluctuosa, Wood, of the west coast, is about two inches 

 high and perhaps a trifle wider. Outside of the pearly shell is a 

 thin coloured layer, brown and white in a bright tesselated pat- 

 tern, moulded over the sculpturing which consists of fine spiral 

 and radiating ridges and rows of faint nodules on the shoulders 

 of the whorls. The operculum is deeply cut, as described above. 



Habitat. — California. 



Genus POMAULAX, Gray 



Shell large, conic, solid, imperforate; periphery keeled; 

 base flat; operculum obovate. 



The Wavy Pomaulax (P. undosum, Wood) is one of the 

 large shells of the California coast. An altitude of five inches and 

 diameter of six inches is not unusal, though the average is lower. 

 A horny epidermis made of fine overlapping lamina; covers the 

 shell to its aperture. It is moulded over a series of nodules that 

 form a ridge like a twisted cord at the outer edge of each whorl. 

 The face of the whorl is further decorated with regular rows of 

 fine knobs and folds. The shell has a thick pearly lining. The 

 shelly layer is pale tinged with brown under the epidermis. The 

 columella has a pearly crescentic groove. Cleaned with acids 

 these pearly top shells are sold at good prices to tourists. 



P. inequale, Martyn.is similar to the last species but smaller, 

 with close, uniform oblique folds crossing all its whorls, and the 

 "twisted cord" at the periphery of each less prominent. The 

 surface is brick red when alive. The base is deeply cut between 

 close spiral ridges. Aperture smooth, lined with white ; columel- 

 lar edge curved, pearly, ending in a tooth below. This species 

 is 2 inches high and 2^ inches in diameter. 



Habitat. — Vancouver Island southward. 



Genus ASTRALIUM, Link 



Shell conical, flattened above and below; young individuals 

 depressed, keeled and spiny at periphery; operculum oval, spiral. 



The Star Shell (A. longispina, Lam.) of the West Indies, 

 has a flattened cone, and triangular, hollow spines all around 

 its thin outer edge, and following the coils toward the apex. The 

 flat base is sculptured by thin laminae, radiating from the deep 

 umbilicus. The whorls above have beside the large projecting 

 sutural spines a thick sprinkling of recurved hollow tubercles. 



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