The Oyster Drill 



dered, forming a steep spire, with nine stout vertical ribs, crossed 

 by fine, close spiral lines. Usually there are two prominent 

 varices, opposite each other. These are sometimes reduced to 

 small size. The lip is thick and set within a border of raised 

 granules. The animal is white except the yellow foot. Length, 

 i to I J inches. Distribution, Massachusetts Bay to Georgia. 



E. Tampaensis, Conr., is more robust, with sharper ribs and 

 shorter canal. Varices scarcely distinguishable. Length, i inch. 



Habitat. — West Coast of Florida. 



THE SMOKE SHELLS 

 Genus TYPHIS, Montf. 



Shell ovate or oblong, with projecting hollow tubes between 

 the three spinose varices ; aperture roundish, prolonged into closed 

 siphonal canal; operculum as in Murex. Species: fifteen recent, 

 eight fossil. Distribution, warm seas. Tropical America, Cape 

 of Good Hope, Indian Ocean, Pacific Islands, China, Australia. 



The Large Smoke Shell (7. grandis, A. Ads.) is a repre- 

 sentative species of this small genus. The ascending tube contains 

 an extension of the mantle margin. The varices are broad, fluted, 

 fm-like, forming a wing on either side of the basal canal. The 

 whorls are angled, the tubes short. Length, ij inches. 



Habitat. — Gulf of California. 



The Four-winged Smoke Shell (T. tetrapterus, Bronn) is 

 distinguished by the four fin-like expansions on the canal, which 

 broaden into wing-like varices below the upcurving hollow tubes 

 that adorn the spire. Length, i inch. 



Habitat. — Mediterranean Sea. 



The Long-horned Smoke Shell (T. longicornis, Dall) has 

 a very long, straight anterior canal, a steep spire set with many 

 upturned tubes, and two or more pointing downward on the 

 body whorl. Length, J to i inch. Gulf of Mexico. 



THE TROPHONS 



Genus TROPHON, Montf. 



Shell fusiform, thin, white, with numerous sharp lamelliform 

 varices; spaces between them, smooth or spirally ribbed; spire 

 elevated; canal open, turned to left ; aperture oval, smooth, often 



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