408 PALEONTOLOGY OF ILLINOIS. 



MONTICULIPORA LAMELLOSA UMch. 



PI. XXXII, fig. 4-4fc. 



Zoarium large, growing upon some foreign object, composed 

 of one or more layers, each from one to four or five mm. in 

 thickness; the type specimen is a large mass composed of six 

 or seven layers. Surface smooth, showing the surface projec- 

 tions of the acanthopores. Walls of zooecial tubes thin, of about 

 the same thickness throughout, though a little thickened at the 

 surface. Zooecia, except just at their origin, direct, about eight 

 in two mm., angular; their apertures also angular. Diaphragms 

 numerous, horizontal, from one-half to their own diameter 

 apart. Cystiphragms few, never arranged in series. Acantho- 

 pores moderately numerous, increasing in size toward the sur- 

 face. 



Cystiphragms are rarely detected in sections of this form, yet 

 the general facies of this species and especially the granular 

 nature of the walls, leave little doubt as to its being a member 

 of the genus Monticulipora,. 



Position and locality: Cincinnati group, Wilmington, 111. 



MONTICULIPORA WINCHELLI Ulrich. 



PI. XLV, flg. 6-tia. 



Zoarium consisting of a number of superimposed layers, the 

 whole from two to twelve mm. in thickness, the layers from one- 

 half to two mm. thick. Under surface provided with a coarsely 

 wrinkled epitheca. Upper surface showing slightly elevated 

 clusters of larger cells, about 4 mm. apart, measuring from 

 center to center. Walls of zocecia rather thin. Zooecia angular, 

 irregularly hexagonal, those of the normal size seven or eight 

 in two mm., those in the clusters from one-third to one-half 

 larger. Apertures angular. Cystiphragms closely set, very large, 

 leaving but a small visceral cavity; occasionally infundibular. 

 Acanthopores apparently wanting. 



Owing to the large crescentic shape and closeness of the cysti- 

 phragms, vertical sections present appearances which at first 

 sight are very puzzling. The tubes seem to be tabulated very 

 differently. This is due to the shape of the Cystiphragms and 

 their not being arranged in the same way in all the tubes. A 



