10 



ILLINOIS STATE GEOLOGICAL SURVEY CIRCULAR 500 



TABLE 2— MEASUREMENTS OF SPECIMENS OF MESOCALAMITES cf . 

 CISTIIFORMIS FROM THE SPENCER FARM FLORA 





Internode 







Number 





Average 







Accession 



length 



Width 



Length/ 



of 



Ridges/ 



width 



Alternating 





no. 



(mm) 



(mm) 



width 



ridges 



cm 



(mm) 



Continuous* 



Termination 



416492 



45 



17 



2.6 



15 



8 



1.2 



a/c 



pointed 



416493 



17? 



7 



2.4 



15 



20 



0.5 



a/c 



unclear 



416432 



50 



20 



2.5 



20+ 



12 



0.8 



a/c 



unclear 



416606 



30 



4.5 



7 



10 



20-25 



0.5 



a/c 



unclear 



416247 



12 



2.0 



6 



7 



30 



0.3 



unclear 



unclear 



416605 



28? 



>8 



3± 



16 



20? 



0.5 



unclear 



unclear 



416262 



16? 



4 



4 



7-8 



30-40 



0.25-0.3 



cont. (a/c?) 



unclear 



416352 



40 



>8 



ca . 5 



18 



25 



0.4 



a/c 



pointed 



416353 



30 



22 



>1.4 



24 



10-12 



0.8-1 



a/c 



pointed 



416261 



19 



2.5-5 



ca. 4 



11± 



17± 







a/c 



unclear 



416495 



20.5 



3.5 



ca. 6 



6-8 



25 



0.4 



a/c 



pointed 









The foil 



owing be 



ar Calamostachys 







416487 



20 



4.0 



5 



12 



30 



0.3 



cont. 







416413 



22 



3.0 



7 



8 



25 



0.4 



cont. ? 







416511 



30 



3.0 



10 



7 



25 



0.4 



cont . 



— 



* a/c = both alternating and continuous. 



TABLE 3 — MEASUREMENTS OF SPECIMENS OF CALAMOSTACHYS ANDANENSIS 

 FROM THE SPENCER FARM FLORA 



Specimen 

 no . 



Length 



of cone 



(mm) 



Width 



of cone 



(mm) 



Length of 



internodes 



(mm) 



Size of 



Length 



Length of 



sporangia 



of bracts 



s p or angio spore 



(mm) 



(mm) 



(mm) 



416375 



— 



- 



3.0 



1 



.6 x 1.2 x 1.0 



416513 



— 



- 



2.2 







.8 x 0.8 x 0.5 



416607 



— 



3 



2.2 





— 



416413 



20 



3 



2.0 





1.5 x 1.0 



416511 



±20 



3 



2.5 





— 



416266 



15 



4 



3.5 





— 



416609 



15 



5 



3 





— 



416414 



10 



4 



2.3 





1 .0 x 0.7 



4 1 64 1 6 



±25 



3 



3 





1 .4 x 0.8 



416608 



__ 



_ 



3.5 









2.4 



3.5 



4.0 



1.2 



1.4 



1.3 

 1.5 



