29 
Maciurea, Bellropho7i, Pleurotomaria, etc. The Cephalopods by 
many specimens of Orthoceras. In above Case 2 D will be seen a 
drawing illustrating this Mollusk as it was situated in its shell 
Living in the outer chamber, a long siphuncle connected the 
animal with the other sections. In the process of geological time 
shells of this type gradually become coiled and the partitions 
between the chambers become more and more complex, reaching 
greatest development in the Ammonites of the Cretaceous period. 
The class then diminishes in size and number, and are represented 
at the present day only by a few species of the Nautilus. 
Several specimens of Eurypterus, of the class of Crustaceans. 
These are large Entomostracans, having their nearest representa- 
tives in the Cyclops of the present day. 
Cup Corals represented by Cyathophyllum. 
Case 2E.— Straight hinged or square shouldered Brachio- 
pods, represented by Sprifera. This is a common genus through 
nearly all geological history, and still exists. Other Brachiopods 
are Rhynchonella and the large and characteristic Penta7nerus. 
T rilobites — Phacops, Dalmanites. 
Case 2F. — Cephalopods of the Orthoceras family — Phrag- 
moceras, Gomphoceras, It will be noted that Mollusks, Brachiopods, 
Crinoids, and Corals make up the larger part of the life of this age. 
Cases 2G, 11 and 3. — Fossils of the Devonian age, or age 
of fishes. Here, for the first time in the earth’s history, vertebrates 
appear. They are fishes belonging to the two orders of Ganoids 
— represented in the present day by Gar -fish and Sturgeon — 
and Placoids, represented by Sharks, Skates, and Rays. 
Cases 2Cr and H. — Star fishes, or Asteroids, represented by 
Furcaster and Roei^ier aster , They are free moving Echinoderms, 
not attached like the Crinoids. Cup Corals are represented by 
several species of Zaphreniis, Sponges by Dictyophyton, large 
masses of which will be seen in this case. Other invertebrates of 
types already mentioned. Pterichtys and Coccosteus, fishes of the 
order of Ganoids. 
Case 3. — One of the earliest representatives of land plants — 
Psilophyton, This belongs to the group of Lycopods, or club 
mosses. The Cephalopods are represented by Go7iiatites. They 
belong to the same type as Orthoceras^ but are coiled and the 
junction of the septa and shell (suture) is zigzag instead of straight. 
