CHAPTER XVI: THE AUGER SHELLS 



Family Terebrid^ 



Genus TEREBRA, Brug. 



Shell heavy, long, taper-pointed, regularly spiral, of many 

 flat whorls; aperture small, notched in front; columella without 

 folds; operculum horny, annular; head large with eyes on tips 

 of tentacles ; foot round in front, elongated behind ; radula present; 

 proboscis large. A single genus of about 170 living and 25 fossil 

 species. Inhabit shallow water in warm seas. 



Few of the members of this tropical family are found in the 

 cold waters of our coasts. These species are small and dull com- 

 pared with the large and highly coloured species represented in 

 museum collections. All have the characteristic tapering spire 

 with many flat whorls. They are usually polished and mottled 

 or banded with some shade of brown on a pale ground. Some 

 are trimmed with nodules upon the whorls. 



The Variegated Auger Shell (T. variegata,Grz.y) is streaked 

 and spotted with brown on a whitish ground colour. A strong 

 raised band revolves below each suture. The remaining part 

 of the whorl is flat and finely striated. Fine wavy folds cross 

 these striations. The raised bands bear prominent cross folds, 

 between which are bright spots of brown. The body whorl has 

 a central band of white dividing the cloudy brown cross streaks. 

 The shell is polished, china-like and heavy. Length, aj to 

 3i inches. 



Habitat. — West Africa, China Sea, Galapagos Islands to 

 Lower California. 



The Spotted Auger Shell (7. maculata, Linn.) is a good 

 type of the tropical members of the family. Heavy, solid, with 

 many closely wound, flattened whorls winding down from a 

 taper-pointed apex, it forms a needle cone of extreme elegance and 

 mathematical exactness. The lower whorls are smooth, the upper 

 ones longitudinally ridged. The ground colour is creamy white. 



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