TRICHOTROPIDAE 167 



is white in color (although the periostracum is yellow-brown), with more 

 prominent spiral threads, and with coarser spiral threads in the young. Found 

 offshore. 



Hipponix barbatus Sowerby (Bearded Hoof-shell) from the same region 

 is limpet-shaped, with coarse, nodulated ribs which are largest on the anterior 

 slope of the shell. The edge of the shell is strongly serrated with cut lines. 

 The periostracum is very shaggy especially on the middle of the anterior slope. 

 Common. 



Family VANIKOROIDAE 

 Genus Vanikoro Quoy and Gaimard 1832 



Vanikoro oxychone Morch West Indian Vanikoro 



Southeast Florida and the West Indies. 



Vz inch in length, solid, strong and pure white. With 3 whorls. Charac- 

 terized by its large aperture, by its deep, narrow, arched umbilicus and 

 straight, rounded, pillar-like columella and by the 10 or 12 beaded, spiral 

 cords on the last whorl. Small axial threads tend to give a slightly cancellate 

 sculpture. Apex glassy and smooth. Suture well-indented. Uncommon in 

 shallow water. 



Superjamily CALYPTRAEACEA 



Faimly TRICHOTROPIDAE 



Genus Trichotropis Broderip and Sby. 1829 



Trichotropis borcalis Broderip and Sowerby Boreal Hairy-shell 



Plate 24d 



Arctic Seas to Maine. Arctic Seas to British Columbia. 



V2 to % inch in length, with 4 to 5 carinate whorls. Shell not very 

 strong, chalky-white and covered with a thick, brownish periostracum which 

 has hairy spicules on the region of the shell's 3 major spiral cords. UmbiHcus 

 chink-like, bordered by a large, spiral cord. Spire usually eroded badly. 

 Numerous, crowded axial threads present. A common cold-water species 

 found from below low water to 90 fathoms. 



Trichotropis cancellata Hinds Cancellate Hairy-shell 



Plate 24b 

 Bering Sea to Oregon. 



% to I inch in length, 5 to 6 rounded whorls bearing between sutures 

 4 to 5 strong spiral cords, between which there may be small axial ribs which 

 produce a cancellate sculpturing. Spire high, rather pointed. Aperture a little 



