39 
Fig. 28 — BRYOZOA. 
F,c. 28: „, Polypora dendroides; an enlargement of a port.cn show.ng -the P» r ■ • 6 ; 
Glauconomc polcherrima, natura. size and enlarged ; c, Arch.medes Wonhen, «" ^ 
and „ » en.arged fragments of portions of the frond, which grows from the edge of the screw, 
forming a broad expansion. 
The fossils of this class may be found in nearly every epoch, 
to a greater or less extent. They are represented in the collection 
under the Chazy and Black River groups only sparingly. In the 
Trenton are some peculiar forms under the generic name Eschar* 
para, in Case c, Sect, i, and others in Sect. 8. Under the Hudson 
River group, in Case d, Sect. 4, there are many forms, especially 
of the Genera Chetctes and Monticulipora and allied forms Under 
the Clinton group, Case d, Sect. 13, will be found forms of Fenes- 
tra, Retepora, &c, and under-the Niagara, in Case E, Sects 4, 5, 
„ and 12, there are many forms not represented in the lower 
