PLATE XLV. 



PAGE. 



Fig. 1. RHOMBOPOBA SUBANNULATA Ulr 648 



1,1 a and 1 h. Three specimens showing mode of branching and faint annu- 



lations. Natural size. 



1 e. A somewhat worn specimen doubtfully referred to this species. Natu- 

 ral size. 



1 <J. Surface of fig. 1, x!2. showing fully matured condition. 

 1 e. Tangential se 'tion of an old example, x25. 



1 /. Surface of flg. 1 a, Showing appearance of young evamples, x!2. 

 1 g. Tangential section deeper than 1 e, showing less mature stage, x25. 

 1 h. Vertical section, x25, showing superior hem'septa and flexuous walls. 



1 i. Transverse section, x25. The transverse lines near the margin do not 



represent the diaphragms but hemisepta. 



Hamilton group, Buffalo, Iowa. 



Prof. A. H. Worthen and E. O. Ulrica's collections. 



Fig. 2. RBOMBOPOBA SULCTPEBA Ulr 649 



2. Fragment, of the natural size. 



2 a. Surface of same, x!2, showing the external features of the species. 



2 6. Tangential section. x25, showing the thick interspaces and acanthopores. 



Hamilton group, Davenport, Iowa. 

 E. O. Ulrich's collection. 



Figs. 3 and 4. RHOMBOPOEA LINEINODIS Ulr 649 



3. Three specimens showing natural size and manner of growth. 



3 a. Surface of right hand example, x!2, 



3 b. Portion of central example, x!2. 



4. Two examples of a more frequently branching variety of this species. 



4 a. Surface of one near its base, x!2. The specimen is either abraded or 



has the granules and apertures obscured by a deposit of calcareous 



material. 



Up. Helderberg. Ohio Falls. 



E. O. Ulrieh's collection. 



Fig. 5. 0EKAYIA DEVONICA Ulr 416 



5. A fragment of a solid branch, showing slight monticules and its irregular 



growth. Natural size. 



Up. Helderberg, Falls of the Ohio. 



5 a. A branching hollow fragment, probably representing another species. 



The surface, however, closely resembles that of flg. 5. 

 Hamilton group, Erie Co., N. Y. 

 E. O. Ulrich's collection. 



