172 A. E. Verrill—The Bermuda Islands; Geology. 
stations 808 and 809, were of the same form as the earlier one I do 
not know. But we found one example in the beach rock (Devon- 
shire formation) near Hungry Bay, associated with foraminifera and 
shells of Cweum, ete. 
b. “ Palmetto Stumps” or “ Sand Pipes.” 
Ficure 56. Puates XIX, XX. 
In many localities and at various levels, often high above the sea, 
but especially in the firm Walsingham limestones, large cylindrical or 
cup-shaped cavities are found, often surrounded by a hardened wall, 
more or less infiltrated with stalagmitic material. They often occur 
in large groups and are frequently connected at the top by a layer 
of indurated red clay. (See above, pp. 62, 72, 120.) 
They are generally believed by the natives to be the casts or molds 
of palmetto stumps, and this view has been adopted by several 
geologists. But Agassiz believed them to be “ pot-holes” made by 
Figure 56.—A ‘‘ fossil palmetto stump,” which has partly weathered out from 
the surrounding softer stone, and shows internal pittings. After Thomson. 
the sea.* Thomson considered them hollow stalagmites, made by 
dripping water in imaginary caverns. Such forms are not peculiar 
to Bermuda. 
Structures very similar to these occur in the white chalk of 
England and in the calcareous rocks of Europe. In England they 
are called ‘“sand-pipes” and “sand-galls.” Examples of various 
sizes are figured by Lyell, in his Manual of Geology, ed. 4, p. 82, as 
*T have shown above (pp. 120, 121), that they are often converted into pot- 
holes, when they occur on the shore ledges. 
