PLATE XXI. 



i'AGE. 

 F'itr. J. CH.ETETEfi Dalei 192 



1. Frajinient. Ifatural sizo. 



In. Portion of the Kvirface of the same. Eularjjecl. 



Fig. 2. Cn.iiTETES RU<;o8Us 193 



•2, Fraameut. jSfatural size. 



Fig. 3. OlI.ETETES APPEOXIM/VTITS 193 



:>. Fragment. Natural sizo. 



'Ja. Portion of tlie surface of the same. Enlarged. 



Fig. 4. Ch-Ktetes ATTRixrs , 194 



•I. Fragment. Natural size. 



4(7. Portion of the surface of the same. Enlarged. 



Fig. 5. Ch.etetes ruLciiELLi'S 195 



."). Fragment. Natural size. 



5a. Portion of the surface of the same. Eulai-ged. 



Fig H. Ch.ETETES SITB-PUTXHELLUS 196 



fi Fragment. Natural size. 



tiff. Portion of the surface of the same. Enlarged. 



Fig. 7. Ch.rtetes Fletcheri , 197 



7. Fragment. Natnial size. 



'ia. Poi'tion of the sui-tace of the same. Enlarged. 



Fig. 8. Cm-ETETES gracilis 198 



8. Fragment. Natural size. 



Sa. Portion of the surface. Enlarged. 



86. Portion of the sui face. Still further enlarged. 



Fig. 9. Ch.etetes delicatulus 199 



9. Fragment. Natural size. 



9a. Portion of the surface of the same. Enlarged. 



Fig. 10. Ch.etetes nodulosus 200 



] 0. Fragment. Natural size. 



II «. Portion (jf the surface of the same. Enlarged. 



Fig. 11. Cn.ETETES Jamesi 200 



11. A somewhat lobate specimen, showing the rounded ends of the branches. Natural size, 



lis. Portion of the surface of the same. Enlarged. 



Fig. 12. Ch.etetes rhombicus 201 



1-2. Fragment, showing the termination of a branch. Natural .size. 



y-ia. Portiim of the surface 01 the same. Enlarged. 



Fig. 13. Ch.etetes briareis 202 



i:!. .\n example, with four primary branche.s springing from the basal cone. Natural s-ize. 



i.ia. Anothei- example, with only two primary branches arising from the basal cone. Natural 



size. 



i:ib. Portion of the surface. Enlarged. 



Fig. 14. Cn.ETETES petropolitanus 204 



14. A small example, apparently belonging to this speei. .-;. growing upon l)ic \:\l\v of a 



IStrophnmctia. 



14a. Portion of the surface of the same. Enlarged. 



14b. Side view of a vary small example of C. petropolifanu>-: having the typical free mode of 



growth, showing tho great comparative height. Natuial .-*ize. 



Fig. 15. Ch.'f^tetes discoideus 206 



l.">. A specimen of the average size, viewed from above. Natural size. 



loa. Concave under surface of the same. Natural size. 



156. Proiile view of the same, showing the great comparative thinness of (he disc. Natural 



size. 



1.5c. Portion of the surface of the siime. Enlarged. 



