

PLATE LVI. 



PAOB 



Fig. 1. ACANTHOCLADIA ANCEP8 Schlothcim 63S 



1. Horizontal section of main stem and portions of two pinnae, xl*. Shows 



' in the lower part the two principal ranges of zooeeia. 

 1 a and 1 b. Vertical and transverse section of midrib, x!8. 

 1 c. Slightly oblique transverse section of one of the lateral branches, x!8. 

 Permian, Poesneck, Germany. 



Fig. 2. PINNATOPOEA ELEGANS Young and Young 615 



Horizontal section of midrib and pinnae, x)8, showing two ranges of 

 zooeeia in both. 

 Carboniferous shales, Scotland. 



Fig. 3. PlNNATOPOBA BETBOFLEXA Y. & Y 615 



Horizontal section ol midiib and pinna'. x!8, showing the lozenge- 

 shaped zooeeia and their peculiar arrangement In the midrib. 

 Carboniferous shales, Scotland. 



Fit,'. 4. PlNNATOPOBA LAIA Y. & Y 615 



4. Horizontal section, xlS, showing a uniserial arrangement of the zooeeia 



in both the midrib and pinnse. 

 4 a. A deeper portion of same section where it passes through the basal 



liiyer. 



Carboniferous shales, Scotland. 



Fig. 5. PINNATOPOBA CONFEBTA Ulrioh. (See also PI. LXVI.) 618 



Horizontal section, x!8. shewing the large biserially arranged zooscia 



in the midrib. 



Keokuk group, Bentonsport. Iowa. 



Fig. 6. PINNATOPOBA TBILINEATA (Meek) 62* 



Horizontal section, x!8, showing the midrib with several pinnae and 

 the base of a lateral branch. The hemisapta are better developed in 

 this species than in any other of this family. 

 Coal Measures, Springfield, III. 



Figs. 7 an 1 8. SEPTOPOBA SUBQUADKANS, Ulr. (See also PI. LXIV.) 629 



7. Horizontal section, x!8. The branches are closer together than usual. 



8. Horizontal section of another branch, x!8. 



Chester group, Chester, III. 





