112 American Se ash ells 



Subfamily CALLIOSTO MATIN AE 

 Genus Calliostoma Swainson 1840 



Calliostoma euglyptum A. Adams Sculptured Top-shell 



Plate 17W 



North CaroHna to Florida and Texas. 



% inch in length, equally wide. Angle of spire about 70 degrees. Sides 

 of whorls slightly concave. Periphery well-rounded. No umbilicus. Whorls 

 with 6 major, well-beaded, spiral cords between each of which is a much 

 smaller, weakly beaded thread. Color dull-rose, sometimes with axial flam- 

 mules of cream. Nucleus pink or, when worn, dark purple. Moderately 

 common in some localities from low tide mark to 3 2 fathoms. 



Calliostoma zonamestum A. Adams Chocolate-lined Top-shell 



Plate 311 



Lower Florida Keys and the West Indies. 



% to I inch in length, slightly wider. Angle of spire about 70 degrees. 

 Sides of whorls flat; periphery sharp; base flat. Umbilicus deep, smooth-sided, 

 white. Whorls characterized by 10 spiral, beaded threads between each of 

 which there is a dark-chocolate line. Base olive with about 5 to 6 fine, brown, 

 spiral lines. A very beautiful and moderately rare species much sought after 

 by collectors. 



Calliostoma roseolujn Dall Dall's Rosy Top-shell 



North Carolina to both sides of Florida and Yucatan. 



% inch in length, % as wide. Angle of spire about 50 degrees. Sides of 

 whorls well-rounded, and with 8 to 9 crowded spiral rows of numerous neat 

 beads. Columella upright, strong, with a slight twist. Color of shell light 

 orange-tan to cream, often with arched splotches of darker color running 

 axially across the whorl. No umbilicus. Aperture pearly-rose. Uncommon 

 from 12 to 100 fathoms. 



Calliostoma pulchrum C. B. Adams Beautiful Top-shell 



North Carolina to Florida, the Gulf of Mexico, and the West Indies. 



% inch in length, % as wide. Angle of spire about 50 degrees. Sides of 

 whorls straight. Characterized by a pair of strong, spiral cords just above the 

 suture which are white with distantly spaced red-brown dots. Rest of whorl 

 pearly-green with 6 to 7 very weak (or sometimes strong) beaded spiral 

 threads. Columella almost upright, its inner side rounded, pearly. No umbili- 

 cus. Moderately common from i to 40 fathoms. 



