PLATE XXXVIII. 



PAGE. 



Fig. 1. TBEMATOPOKA CALLOPOBOIDES Ulr 420 



1. Natural size view of the type specimen. 



1 a. Surface of same, x!2. 



1 b. Tangen'ial section, showing small acanthopores, x!8. 



1 c and 1 d. Two portions of a vertical section, x!8. 



Top of Trenton, Alexander Co., Ill, 

 Illinois State Museum. 



Fig' 2. MONOTKYPELLA CBA8SIMUBALIS Ulr 452 



2 and 2 a. Two examples of this species showing mode of branching and 



size of stems. The drawing of the cells on 2 a, is not natural. 



2 1). Surface x!2. In other examples the interspaces are not flattened, and 

 the sloping areas meet. 



2 c. Tangential section of an example in which the zooecia are almost iso- 

 lated, x!8. 



2 d. Tangential section of another specimen in which the zooecia are mainly 

 in contact x35. 



2 e. Vertical secjion of same specimen that furnished 2 c, x!8. It shows the 

 strongly tabulated interspaces. 



2 /. Portion of a transverse section, x!8, showing rhomboidal form of zoo?cia 



in the axial region. 



Cincinnati group, Wilmington, 111. 



Illinois State Museum. 



Fig. 3. HOMOTBYPA ABBUSCULA Ulr 409 



3. Part of a fine example of this species. Natural size. 



3 a. Surface of one of the branches x!2, showing the oblique apertures. 

 3 I*. Tangential section, \ is. 



3 c. Vertical section, x!8. This example was not sufficiently developed to 



show cystiphragms. Section since prepared prove that in fully matured 



examples there are two or three of those structures near the surface 



in each zooecial tube. 



Blrdseye limestone, High Bridge, Ky. 



E. O. Ulrich's collection. 



Fig. 4. MOHOTBYPA BECTIMUBALIS Ulr 462 



4. A sub-hemispheric example. Natural size. 



4 a. Tangential section, x!8. with a small portion at the upper right hand 



corner, x50. 



4 6. Vertical section, x is, showing the remote diaphragms and thin straight 

 walls. 



Cincinnati group, Alexander Co., 111. 

 Illinois State Museum. 



