Fic. 
Fig. 
Fia. 
Fia. 
Fia. 
Fia. 
6 
[SpA i OG Oe WEIL 
HELMINTHOIDICHNITES MARINUS. 
. A common form of burrow or trail, that occurs on the surface of the slate, associated with ~ 
the medusx. It has the appearance of a number of narrow trails made on a broad trail, 
such as is represented by fig. 2. 
A broad, smooth trail on the surface of the slate. 
. Cast of a boring in which the mud was pushed back by the animal that made it. 
. Narrow trails as they occur on the surface of the slate. 
All of the above occur in the same band of slate with D. asteroides. 
DACTYLOIDITES ASTEROIDES (p. 41). 
. A small specimen showing traces of the central disk. 
. A specimen preserving the exumbrella lobes and a peculiar flattening of the subumbrella 
lobes. 
158 
