PLATE XIII. 
Figs. 1 to 11. ESCHAROPORA CONFLUENS, 0D SDP.......-...0--ee eee oe aalelelersistemnisseieta s,sreminrsias mado dONb se 171 
1. A specimen that preserves the pointed articulating base; natural size. 
2. Well preserved fragment, the surface of which is enlarged in fig. 5. 
3. Portion of a large specimen with comparatively remote bifurcations and obscure monti- 
cules; natural size. 
4. Incomplete basal part of another large zoarium; natural size. 
5. Surface of the original of fig. 2, x9. The line above indicates the contour of the surface 
in a transverse section. 
6. Tangential section, X18, of a well preserved example. The figure embraces about two- 
thirds of the width of the branch. the right side being marginal. 
7. Several zooecia of the same section, X35, showing the mural lineation. . 
Another portion of the same section, 18, showing the prostrate part of the zoccia. 
9. Left half of another section, 18, prepared from a specimen in a less favorable (the usual) 
state of preservation. In this example the marginal zocecia were uncommonly large 
10 and 11. Transverse and vertical sections X18. 
Middle third of the Trenton shales at Minneapolis. 
ge 
Figs. 12 and 13. EscHAROPORA (?) LIMITARIS, 0 Sp. Or Var......-- eialoraleser atarerntetel sterereversy sister einer Seacoos ~) llr 
12. A very large specimen, provisionally referred to this species; natural size. Middle 
third of the Trenton shales at Minneapolis. Survey Museum. Reg. No. 5930. 
13. A specimen of the average size of the species as it occurs in the lower third of the 
shales at Minneapolis. (For internal structure see figure 9 on page 172.) 
Figs. 14 to17. PH4&NOPORA INCIPIENS, D. Sp..... Snodadounuoopadoonn Doon aatoagod sonsbnepdocnasscna 2 ult! 
14. A fragment of the natural size and a partof it X18. Trenton limcetone: Montreal, Can. 
15. The basal part of a zoarium from the Trenton limestone at Chimney Point, Vermont. 
16. Tangential section, *18, of a specimen from Montreal. 
17. Tangential section of another specimen from Montreal, X28, showing structure imme- 
diately beneath the surface. 
Figs. 18 to 21. ST1cTOPORELLA EXIGUA, 0. Sp.* 
18. Portion of the delicale zoarium of this species, natural size. 
19. Surface of oneof the branches *18. 
20. Tangential section X28. 
21. Transverse section *18. 
Trenton limestone, Montreal, Can. 
Figs. 22 to 26. PH@NOPORA WILMINGTONENSIS, 0 SP..........--+ BAO Ods SAOOn OO sce Ho nonapnaeatos a 947i) 
22. Fragmentary example of the natural size. 3 
23. Surface of same <9. 
24. Two portions of a tangential section, <18, the upper showing the appearance just 
beneath the surface, the lower just over the prostrate part of the zocecial tubes. 
25. One of the zocecia and portions of the adjoining ones X35 to show the minute structure 
of the walls. 
26. Vertical section, x18. 
*The description of this interesting species having unfortunately been omitted from its proper place in the text, the 
following brief diagnosis of its peculiarities is added here: 
Zoarium consisting of slender and frequently dividing branches, not exceeding 1.5 mm. in width; margins parallel, 
scarcely sharp. Zocecial apertures oval, more or less oblique, arranged in eight or nine longitudinal rows, six or seven in3 
mm,, between longitudinal ridges; diagonally three or four inl mm. End interspaces two or three times as long as the 
width of the space between the ridges, rsiing distally, usually with two elongate shallow pits or furrows. 
All that is known of the interior is shown in the figures. 
The types were collected at Montreal, Oanada, in the Trenton limestone, by Mr. T. CO. Curry, for the Peter Redpath 
Museum, from which institution they were obtained by the author in exchange for other fossils, 
