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resented by large slabs containing Leptoena, also many species 
of Lingulella, Lingula, and Rhynchonella- Species of the latter 
genera exist at the present day. They afford a remarkable ex- 
ample of the power of a genus to survive the vicissitudes of 
time. Glyptocrinus, locrinus — Crinoids, the class of Echino- 
derms most abundant in early times. Attached by a jointed 
stem and bearing many-branching arms, they have been appro- 
priately termed sea-lilies. 
Arthrophycus — supposed to represent the leathery stems of 
seaweeds. Some authorities, however, regard this fossil as rep- 
resenting the markings of worms. 
Eridophyllum — corals of the Cyathophylloidoe or cup-coral 
family. Halysites — corals of the Halysitidae or chain-coral 
family. Nearly all Silurian corals belong to these two or the 
Favositid family. 
Streptorhynchus — A representative Brachiopod. Orthoceras — 
Many specimens illustrating the size and distribution of this Silu- 
rian Cephalopod. The several sections show that the shell was 
divided by cross partitions into chambers. The animal occu- 
pied only the end chamber, but a long tube or siphuncle con- 
nected the others to its body. 
Niagara and Lower Helderberg epochs. — Favosites, Halys- 
ites — Corals. Eucalyptocrinus — Crinoids. llloenus — Trilobites. 
Bythotrephis — probably marine Algae. Pentamerus — a large and 
abundant Brachiopod characteristic of the Niagara beds of the 
Mississippi Basin. Spirifer, Rhynchonella — other common Brach- 
iopods. Eurypterus — Crustaceans closely allied in structure to 
modern Scorpions, but being w^ater breathers are classed with the 
Crustacea. A large number of specimens from the Waterlime 
group of New York. 
Foreign Silurian fossils. From the Wenlock limestone of En- 
gland, several specimens of Periechocrinus, Cyathophyllum and 
others. From the Bohemian beds, several species of Graptolites, 
the genera Phacops and Dalmanites among Trilobites, and many 
specimens of the Orthoceras family. 
Fossils of the Devonian Age or age of fishes. The fishes 
which by their size and abundance characterized this age, be- 
longed to two orders — Ganoids, represented at the present day 
Ly the garfish and sturgeon, and Flacoids, the order which in- 
cludes sharks, skates and rays. They differed in many respects 
