Handbook of Paleontology 141 



fects every kind of station and is as much at home at 

 considerable depths as at low-water mark. The shell 

 is about three inches long, marked with revolving- 

 ridges and transverse furrows and with a velvety 

 brown skin. This species ranges from Cape Hatteras 

 to Greenland, the Arctic ocean and northern coasts 

 of Europe. In England and Scotland it is used as a 

 food under the name of "whelk." Along the Maine 

 coast it is found almost everywhere at just below low- 

 tide level, but south of Cape Cod it lives in deep water 

 down to a depth of 3900 feet. The Ten-Ribbed Snail 

 (Chrysodomus decemcostatus) is one of the striking 

 shells of our northeast coast. It is abundant just be- 

 low low-water mark and is often found associated with 

 the above, but not quite so common. It is fully three 

 inches in length, yellow-brown in color and has ten 

 ridges. This shell is one of the favorite abodes of 

 Hermit Crabs when empty. Snails related to the Key- 

 Hole Limpets and inhabiting our Pacific rocky coasts 

 might be included here because the wide commercial 

 uses of the shell in jewelry, inlaid work etc. has made 

 them so well known. These are the Abalones (Halio- 

 tis), known in England and the Channel Islands as 

 Ormers or Sea-Ears. The shell is spiral but so greatly 

 flattened that the spiral appearance is lost. It is six 

 to eight or nine inches long. These animals are vege- 

 table feeders. They cling to the rocks at low tide so 

 tenaciously that skill is required to remove them with- 

 out breaking the shell. Before it is polished the outer 

 side of the shell is rough and unattractive; within is 

 a beautiful, highly colored, pearly luster. The shell 

 shows rainbow colors or it may be red or very dark 

 green. The Common Edible Mussel found on our 



