BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA 

 VOL. 3, PP. 253-282, PL. 8 MAY 24, 1892 



A REVISION AND MONOGRAPH OF THE GENUS CHONO- 

 PHYLLUM. 



BY WILL II. SHERZER. 



( Read before the Society December -Jo, 1891.) 



CONTEXTS. 



Page 



Introductory 2.">4 



Historical and Descriptive 254 



Type Species 257 



Generic Characters 258 



Growth 258 



Outer Covering 259 



Calyx . 259 



Septa 259 



Dissepiments 2(12 



Central Area 262 



Classification 2(>:'> 



List of Species 263 



Results of defective Definition 263 



1 . ( 'honophyttum perfoliatum 263 



2. < honophyttum elongaium 266 



:;. ( 'honophyttum niagarense 266 



4. ( 'honophyttum magnificum 267 



5. ( 'honophyttum belli 268 



6. ( nonophyttum ellipticum 269 



7. Chonophyllum ponderosum 270 



8. < honophyttum sedaliense 272 



9. < 'honophyttum vadum 27-! 



10. Chonophyllum capax 27:! 



I Ascription of New Species 27 1 



( 'honophyttum pseudohelianthoides 275 



f 'honophyttum greenei 275 



Nearest Relatives 276 



< ieneral Relations 276 



Omphyma 277 



Ptychophyllum 278 



( hjathophyllum 27'. • 



Horizons and Distribution 280 



XXXIV Bum Gkoi Sim \m.. Vol 3, 1891. (253) 



