14 GUIDE TO THE FOSSIL INVERTEBRATE ANIMALS. 
Gallery XI. 
Wall-case 
7o. 
Wall-eases 
7, a 
Wall-case 
8 . 
Gallery X. 
Several of these have a curious structure which produces in 
them a close resemblance to the skeletons of corals. Some 
larger masses of rock e.xhibiting tlie same structure are in 
the N.E. corner of the Gallery. 
Further examples of concretions and other markings 
produced in various ways, not themselves organic, but 
curiously simulating organic objects, .such as a liuman 
skull, the tootli of an elephant, a dog’s head, plants, and 
fruits, are exhibited in order to impress upon beginners in 
the study of fossils the truth that here, if anywhere, things 
are not always what they seem. 
The term “ fossils,” as has already been said, is applied 
not only to the remains of animals and plants, but to various 
traces left by them. The footprints of many animals with 
which we are more or less familiar are easily recognised, and 
many such, exhibited in Wall-cases 8, 9, and 10 on the east 
wall, are descrilied in the Guide to the Fossil Heptiles. The 
more lowly animals, however, produce tracks which are less 
well known, and while certain markings found in the rocks 
can reasonably be explained by reference to the tracks and 
imprints of animals or plants now living, others still lack 
a convincing explanation. Flere may be seen tracks 
ascribed to marine worms, crustaceans, and jelly-fi.shes ; 
others, which have been ascribed to fossil plants and have 
received learned names accordingly, are now supposed to 
be either the tracks of some animal, such as a worm, or 
even the markings left by currents or eddies in tlie water. 
Markings obviously ascribable to such inorganic agencies — 
for example, ripple marks and the prints of rain drops — have 
been found in rocks of all ages, appearing just like the 
“ribbed sea sand” of to-day, or the rain prints newly formed 
on any wet surface of mud or sand, such as the stretches left 
when the tide goes out at the Bay of Fundy. 
PROTOZOA. 
Entering Gallery X, either from that last described or from 
the Gallery of Fossil Reptiles, No. IV, we pass down its left or 
western side to the far end. Here are exhibited the remains 
of the lowest forms of animal life that are preserved as 
fossils. These are the Foraminifera and the Radiolaria, two 
sections of the Phylum or great gi'oup Protozoa (first, i.e. 
■simplest, animals). 
