32 
from the Water Lime group of New York. These are Crustaceans 
of the order of Entomostraca, having their nearest modern repre- 
sentative in Cyclops, a microscopic fresh water animal. 
Case 2F. — Foreign Silurian fossils. From the Wenlock 
limestone of England, several specimens of Periechocrinus^ a 
large and beautiful Crinoid, Cyaihophyllum, a Cup coral, and 
others. From the Bohemian beds, several species of Graptolites, 
the genera Phacops and Dalma7iites among Trilobites, and many 
specimens of the Orthoceras family, including Phraginoceras and 
Gomphoceras. 
Cases 2Gr, H and 3. — Fossils of the Devonian age or age 
of fishes. The fishes which by their size and abundance charac- 
terized this age, belonged to two orders — Ganoids, represented at 
the present day by the gar-fish and sturgeon, and Placoids, the 
order which includes sharks, skates and rays. They differed in 
many respects from the fishes of the present day however, the 
Ganoids being covered with thick, bony scales, having teeth of 
reptilian characters and jointed, paired fins. The Placoids had 
cartilaginous skeletons, no scales, no gill covers, and other embry- 
onic characters. 
Case 2 G. — Lower Devonian fossils of the Corniferous period. 
Favosites — Honey-comb corals. Heliophylhun — Cup corals. 
Ophiura^ Loriolaster — Asteroids similar to modern starfishes. 
Being free moving Echinoderms, they mark the introduction of a 
higher type than the attached Crinoids. Macropetalichthys — a 
Ganoid fish. 
Case 2 H. — Lower Devonian fossils. Syringopora — Chain 
corals. ZaphrentP — common and characteristic cup corals. 
OrthiSy Atrypa, Spirifer — Brachiopods. Coccosteus — a typical 
Ganoid from the Old Red Sandstone of Scotland. 
Case 3 A. — Middle Devonian fossils. Psilophyton — one of 
the earliest of land plants. It belongs to the group of Lycopods 
or club-mosses. HoloptychiuSy GlyptolepiSy Diplopterus — ^Pfishes 
from the Old Red Sandstone of Scotland. These are nearly all 
Ganoids, as may be seen from the large, bony scales with which 
they are covered. Cyathophylluniy Cystiphylluniy Zaphrentis — 
Cup corals. 
Case3B. — Upper Devonian fossils. Large, polished masses 
of Acervularia from Iowa, a honey-comb coral. Dictyophyton — 
large masses from New York, belongs to the class of sponges. 
Aspidosomay Furcaster — Asteroids. Spirifer y Orthis — Brachio- 
