CHAPTER XXIII: THE TUN SHELLS. WINE JARS. 



FIG SHELLS 



Family Doliid.^ 



Shell thin, ovate or sub-globular, with stout spire and 

 swollen body whorl; generally with strong spiral ribs; aperture 

 generally wide, with canal at base; operculum only in immature 

 stages; body large, with spreading mantle; head large; eyes 

 on sides of tentacles; proboscis remarkably large and long, 

 flexible; foot lobed, spread out into a truncated front margin in 

 which there is a horizontal groove. A small family of large 

 mollusks living in seas of the tropics. Sometimes called "wine 

 jars," because they are so capacious. 



Genus DOLIUM, Lam. 



Shell almost globular, with wide mouth ; lip ruffled ; columella 

 channeled; basal canal straight. Used for lamps, vases, etc. 

 Fifteen species. 



The Helmet Tun Shell (D. galea, Linn.), one of two species 

 found on our coast, is a good type of the family. The shell is eight 

 to nine inches long and fully as broad. Unlike the conchs and 

 helmets, the tun shells are thin and light in weight, though large. 

 The spire is small and sunken, with a deep suture in the large 

 body whorl which constitutes the greater part of the shell. The 

 surface has a series of parallel, deep cut, revolving grooves crossed 

 by many faint lines of growth. The even fawn colour of the 

 exterior is brightened by dashes of darker brown on lip, columella 

 and spire. The umbilicus is narrow and deep. 



Habitat. — North Carolina to Brazil. 



The Partridge Tun (D. perdix, Linn.) is marked with 

 crescents of white on a brown ground colour, strikingly resembling 

 the plumage of a partridge. The spire of this species is much 

 elevated. The unusual range is noteworthy. Length, 5 to 9 

 inches. 



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