PLATB LV— OonUimol. 



TrEMATOI'OKA (OuTllOrORA?) TRANSVERSA. 

 Page 187. 

 See Plate 56. 

 Pljf. 12. An enlargement of a longfitu<linal section, showing: the manner of growth of the cell tubes, and 

 the iuterapertural S])a(;e. (X •>.) 



Uauiiltoii {f I'oup. Hamburg, Lake Brie shore, Erie cowdy, N. T. 



TrEMATOPOKA (OrTHOPORA?) ORBIPORA. 

 -I.V!:' Pagfo 188. 



See Plate .^B. 

 f\g. IS. An enlargement, .showing the fonn and disposition of the cell apertures, and the chai-acter of the 



'• int4'rai>ertural Bjiace. (X H.) 



Fig. 14. An enlargement of a longitudinal section, showing the manner of growth of the cell tubes, and 

 the intercellular space. (X t! ) 



Hamilton group. iV«ir Ca7umdaiguu lake, N. Y. 

 : '■ I ;,r. I ; ;;()'|< il /.I. 



ACANTHOCLEMA SOUTULATUM. 



Page lao. 



See Plate 56. 



Fig. 15. An enlarg^ement of a longitucHnal section, showing the filiform axi.s. the cell tubes anil the inter- 



Imiji Bwiiu mediate tubuli fonued by the nodes. (X (>.) 



Hamilton group. N(ar Dri.sden, N. Y. 

 Pig. 16. An enlargement, showing the form and disposition of the cell apertui-es, the alternating nodes, 

 . .ij^,j. I and the longitudinal ridges not coales<:ing between the cell apertui-es. (X 6.) ; 



Hamilton group. Western New Yi>rk. 

 Kg. 17. An enlargement, showing the form and dis|iosition of the cell apertures, \hv. longitudinal ridges 

 coalescing between the cell apertures, an<l the prominent nodes at the point of junction. (X 6.) 

 Hamilton group. Near /Jrenden., iV. Y. 



ACANTHOCLKMA HaMII.TONENSE. 



Fig. 18. An enlargement, showing the iri-egulai- form and disx)Osition of the cell apertures; interapei-tural 

 pits obsi>lete. (X •). ) 



Fig. 19. A still farther enlargement, showing more plainly the characters i-epresente<l in fig. 18. (X 18.) 



Fig. 20. An enlargement, showing th(! form an<l disposition of the cell apertui'es, and the sinuous longi- 

 tudinal ndges. (X 6.) 



Hamilton group. IVt.H WiUianin, Ontario. Caiiada. 



Kg. 21. An enlargement, showing the regular disposition of the cell apertures, the interapei-tural pits, 



t.. flDiutiAu.! »"'l*'^'"""""^"'ise8- (X 18.) uiL'iiW'/ 'I 



Hamilton group. West Hamlmrg, Erie coimiy. If ,x. • 



Fig. 22. An enlargement of a longitudinal section, showing the intercellular structure ; the section is a little 

 to one side of the center of the branch, and consequently the filiform axis is not seen. (X ti.) 



Fig. 23. An enlargement, showing both a regular and irregular disposition of the cell apertui'es. (X 6.) 



Fig. 24. An enlargement from a macerated specimen, showing the spiral arrangement of the cell aper- 

 tures more distinctly than the longitudinal. (X 18.) 



Fig. 25. A still farther enlargement of the specimen represented l)y fig. 23, showing more distinctly the 

 irregular form and disitosition of the cell apertures. (X 18.) 



Fig. 26. An enlargement, showing large cell apertui-es regularly disposed, the interapertural pits, and 

 their sinuous lidges. (X 18.) 



Hamilton group. VVest Williatns, Ontario, Canada. 



TrEMATOPORA (OutHOPORA) BI8P1NULATA. 



Page 182. • 



See Plate 5(i. ,. . , ;., 



Fig. 27. An enlargement, showing indistinct cell apertures, prominent nodes and interrupted longitudiniU 

 ridges. (X 6.) ' ■1)4 itoJliiii 



Hamilton group. Moseow, Livingston, cowdy, N. T. 

 Kg. 28. An enlargement of a longitudinal section, showing the iuternal structure neai' the surface, the 

 cell tul>es and the intercellular tidiuli formed in the course of growth by the hollow nodes. (X 6.) 

 Fig. 29. An enlargement, showing the form and regular iliK|>(>sition of the cell ajiertures, the interapertural 



nodes and the longitinlinal 7-idges. (X •)•) 

 Kg. 30. An enlargement, showing a regular disposition of the cell apertures, and also a somewhat irregular 

 order above. 



Hamilton gninp. Darlen, Genesee county, N. Y. 



