OF DENISON UNIVERSITY. 
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Fzg-. 7. PhcBnopora fiznbriata, James ; a typical frond, parted along the epithe- 
cal membranes; branches frequently found with a looser arrangement. 
Fig. 8. Pachydictya emadata., n. sp ; the type specimen. 
Fig. 9. Pachydictya bifurcata^ ( Van Cleve) Hall; a large frond showing in places 
a pseudo-anastomosis of the branches. 
Fig. 10. Pachydictya bifurcata^ var. instabilis, n. var ; one of the extreme 
forms. 
Fi%. II. Pachydictya turgida., 71 . sp , a typical form. 
F'ig. 12. Pachydictya obesa, n. sp ; the basal portion of a frond, its articulating 
end not discovered; the frond usually widens considerably above and is often de- 
cidedly undulating. 
Fig. 13. Rhinopora verz'ucosa, Hall ; a, a fragment showing raised branching 
lines ; b, a similar specimen in which weathering has caused the same to appear as 
depressed veins ; c, a specimen in which the cells at the junction of the veins have 
become somewhat more prominent, forming low tubercles. 
Fig. 14, Prasopora pai'inula. n. sp ; the type specimen. 
PLATE XVI. 
Fig. I. Phcenopoi'a platyphylla, James ; a frond, parted along the epithecal 
membrane. 
Fig. 2. Phcenopoi'a magna, Hall and Whitfield ; a frond, parted along the 
epithecal membrane. 
Fig. 3. Phcenopora multijida, {Van Cleve) Hall; a typical specimen from the 
collection of Mr. Geo. Caswell ; parted along the epithecal membrane. 
Fig. 4. Monotrypella conjluens, n. sp ; a, a branch ; b, a typical gnarled ex- 
pansion. 
Fig. 5. Callopoi'a magnopora, n. sp ; a branch. 
P'ig. 6. Callopoi'a Ohioensis, n sp ; a branch. 
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PLATE XVII, 
Fig. I. Phylloporina angulata, Hall; a, celluliferous side ; b, non-cellulifer- 
ous side ; c, a tangentitial section. 
Fig. 2. Hemitrypa Uli’ichi, n. sp; a, the network covering the celluliferous 
side ; b, the non-celluliferous side ; c,.a tangential section. 
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