PLATE XXII. 



Fig. 1. CH.T5TETES FRONDOsus, D'Orb. (?) 208 



1. A young and nearly perfect specimen. Natural size. 

 la. Transverse section of a fraj^ment Xatiiral siaa. 

 16. Portion of tlie surface. Ealarged. 



Fig. 2. Ch/etetes clathratulus 209 



2. Surface of a fragment, enlarged to show the arrangement of the calicea in intersecting 



diagonals and the low tnheroftities. 

 2a. Transverse section of a large nxpansion. Natural size. 

 26. Portion of the surface. Greatly enlarged. 



Fig. 3. Ch^tetes Ortoni 211 



3. A small specimen, growing upon Strophomena alternata, Conrad. A'atural size. 

 3a. Portion of the same. Enlarged. 



36. A few calices ot the same, greatly enhirged, showing the tuberculated margins. 



Fig. 4. Ch^etetes Newbeeryi 212 



4. A specimen, apparently nearly perfect. Katnral size. 

 4a. Portion of the surface of the same. Enlarged. 



Fig. 5. ClI.Ti^TETES petechialis 213 



5. Several individuals, in different stages of growth, attached to the exterior of Chcetetes 



frondosus. Natural size. 

 .5a. A single colony of the same. Enlarged. 



Fig. 6. Ch.'etetes corticans 210 



6. A specimen forming a thin crust upon an Orthoceras. Natural size. 

 6a. Portion of the surface of the same. Enlarged, 



Fig. 7. Constellaria polystomella 215 



7. A fragment. Natural size. 



7a. A single star of the same. Enlarged. 



Fig. 8. COLUMNOPORA CRIBRTFORMIS 187 



8. A small specimen, in which the tubes are rounded and have thick walls, viewed from 



above. Natural size. 

 8a. Two calices of an older example. Enlarged. 

 86. Interior of a corallite, showing the septa and the mural pores. Enlarged. 



Fig. 9. Ch.etetes sigillarioides 203 



9. A fragment. Natural size. 



9a. Portion of the surface, where the corallites exhibit secondary calices. Enlarged. 

 9&. Portion of the surface tn another specimen, in whicli the corallites only sometimes exhibit 

 seiiondary calices. Enlarged. 



Fig. 10. Palteophyllum divaricans 220 



10. A small specimen, with a single lateral bud. Natural size. 

 10a. Another specimen. In which four coi'allites have been produced. Natural size. 

 ^ 106. Sketch of some of the septa, showing how the primary septa coalesce internally and form 

 vesicular tissue. Enlarged. 



