PLATE XXII. 



PAGE. 



Fig. 1. Ch.ei'Ktes froxdosus, D'Orb. (?) •. 208 



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



la. Transverse section of a fcajjinent Natural sizo. 



ib. Portion of the surface. Eularged. 



Fig. 2. Ch.etetes clathratulus 209 



2. Surface of a fragment, eulargetl to sliow the arrangement of the calicea in intersecting 



diagonals anil the low tuberosities. 



'■2a. Transverse section of a large expansion. Natural size. 



2&. Portion of the surface. Greatly enlarged. 



Fig. 3. Ch-Etetes Ortoni • 211 



3. A small specimen, grow^ing upon Strophomena alt<'i'natn, Conrad. Natural size. 

 3a. Portion of the same. Enlarged. 



36. A few calices of the same, greatlj' enhirged, showing the tiiberculated margins. 



Fig. 4. Cn.ETETES Newberrvi 212 



4. A .".jjecimen. apparently nearly perfect. Natural size, 

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



Fig. 5. Ch.etetes petechiali.s 213 



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



frondosus. Natural size. 



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



Fig. 6. Ch.etetes coRTicAxs 210 



(i. A specimen forming a thin crust upon an Orthocercls. Natural size. 



da. Portion of the surface of the same. Enlarged, 



Fig. 7. CONSTELLARIA POLYSTOMELLA ., 215 



7. A fragment. Natural size. 



la. A pingle star of the same. Enlarged. 



Fig. 8. COLUMNOPORA CRIBRTFORMIS , 187 



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



above. Natuial -size. 



Sa. Two calices of an older example. Enlarged. 



t^6. Interior of a corallite, showing the septa "and the mural pores. Enlarged. 



Fig. 9. Ch.etetes sigillarioides 203 



!). A fragment. Natural size. 



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



dh. Portion of the surface in another specimen, in which the corallites only sometimes exhibit 

 secondary calices. Enlarged. 



Fig. 10. Pal,i50phyllum divaricans.. 220 



10. A .sm.iU spccin\en, with a single lateral bud. Natural size. 



10a. Another .•<iieriuu ii, in which four corallites have been produced. Natural size. 



10?>. Ski'tili of some of I he septa, showing how the primary septa coalesce internally and form 

 vesicular tissue. Enlarged. 



