XIV 
SYNOPSIS OF GENERA . 
Examples : Chatties ( Monotrypclla ) arhusculus, pi. ix, figs. 1-3, 6-8. 
Chatetes ( Monotrypella ) abruptus, pi. ix, figs. 9-11. 
Ptychonema, n. s. g. [Type, Chaetetes tabulatus, Hall.] 
Corallum massive or ramose ; composed of thin-walled, strongly corrugated 
cells which are apparently without diaphragms in the typical species. 
Example: Chatties ( Ptychonema ) tabulatus, pi. ix, figs. 12-15. 
Trematopora, Hall (Pal. N. Y., vol. ii, p. 149. 1852). 
[Type, Trematopora tuberculosa, Hall.] 
Zoarium ramose ; branches solid. Cells arising from the center of the branch 
and continuing contiguous to each other until near the surface where they sep¬ 
arate, becoming cylindrical and more or less surrounded by spiniform tubuli and 
interstitial cells. Tabulae usually present; no mural pores. Cell apertures 
oval or circular. Interapertural surface sometimes showing evidences of the 
interstitial cells beneath, but never with conspicuous open mesopores. 
Although no true examples of this genus has been noticed among the mate¬ 
rials used for the present volume, it is thought best to give a brief synopsis of 
the genus for comparison with the sub-genera arranged under it and also other 
closely allied forms. 
Trematella, Hall (Report of State Geologist for 1886, advance sheets. Expl. 
pi. 25. 1886). [Type, Trematella annulata, Hall.] 
Zoarium ramose, solid. Cells tubular, in contact below, diverging near the 
surface, intersected by septa. Interapertural surface marked by pseudo-pores. 
Examples: Trematopora (Trematella ) annulata, pi. xxv, figs. 22,23; pi. xxvi, 
figs. 1, 2. 
Trematopora ( Trematella ) glomerata, pi. xxv, figs. 4, 5. 
Orthopora, s. g., Hall (Report of State Geologist for 1886, advance sheets. 
Expl. pi. 25. 1886). [Type, Trematopora regularis, Hall.] 
Zoarium ramose, solid. Cell apertures arranged in parallel longitudinal 
rows. Intercellular space solid, or occupied near the surface by minute tubuli 
destitute of septa. 
Examples: Trematopora ( Orthopora ) regularis, pi. ix, figs. 1-8; pi. xiii, figs. 
1-3 ; pi. xxiii, fig. 1. 
Trematopora ( Orthopora) subquadrata, pi. lv, fig. 10; pi. Ivi, figs. 1, 6. 
