PLATE I. 



*Fig. 1. — Rhombocladia delicata Rogers. 



1. A specimen, natural size. 

 la. Cross-section of same, X5. 

 16. Horizontal section, X 27. 



Ic. Vertical section, X 50. (This figure is upside down. It is an oblique 



section, so that openings of the zoecial tubes are not shown.) 

 Id. Portion of reverse surface, X27. 

 Fig. 2. — Cystodictya inequimcirg inata Rogers. 



2. Specimen, natural size. 



2a. Transverse section of same, X^. 

 26. Portion of surface, X 27. 

 Fig. 3. — Strehlotrypa idrichi Rogers. 



3. A specimen, natural size. 

 3a. Portion of stem, X 27. 



Fig. i.—Fenestella hexagonalis Rogers. 



4. Obverse side, X27. (The nodes are hardly prominent enough.) 

 4a. Reverse side, X27. (The nodes should cover all the elevated part 



of the drawing.) 

 Fig. 5. — Fenestella dentata Rogers. 



5. Obverse side, X27. 



5a. Profile view of a branch, to show dentate appearance of carina, X 27. 

 Fig. 6. — Fenestella kansasensis Rogers. 



6. Obverse side, X 27. 



* When these figures were made, the obverse side of the species had not been seen ; conse- 

 quently uo drawings of it appear. 



