Ztb S. WELLEB FAUNA OF THE FERN GLEN FORMATION 



1869. Cladochonus crassus Rofe. Geological Magazine, volume 6, page 352, fig- 

 ures 2. 3. 4. 4a. 



1879. Monilopora crassa Nieb. & Eth.. Jr.. Geological Magazine. Decade 2. vol- 

 ume 6, page 293, plate 7. figures 2a-f. 



1879. Monilopora crassa Nicb.. Pahjeozoic Tabulate Corals, page 223. figures 

 32a-f. 



1899. Mot Hopora crassa Grabau. Proceedings of tbe Boston Society of Natural 

 History, volume 28, page 410. 



Des iption. — CoraUum consisting of a tubular, stolon-like base at- 

 tached to a ciinoid stem, which at intervals gives origin to curved, conical 

 corallites. The eoralluni commences as a ring of corallites with their 

 connecting basal stolons encircling the ciinoid column ; adult colonies 

 n leave their ring-like habit of growth in large measure and appear 

 as confused aggregations of corallites surrounding the crinoid column. 

 Not infrequently the entire coral becomes completely buried in the 

 crinoid column by reason of the continued growth of the latter, so that 

 only the rims of the calices project beyond the surface of the column. 

 The individual corallites are conical in form and rather thick walled. 

 with a diameter of from 2 millimeters to 6 millimeters at the rim, and 

 are entirely free from tabula?. The septa are all but obsolete, excec 1- 

 ingly faint septal ridges being discernible in only a few individuals. 



_" varies. — This species seems to be entirely identical with the British 

 form. It differs from 31. beech eri Grabau, from the Crawfordsville 

 crinoid beds, in its much smaller size, its shorter corallites, and in the 

 greater regularity of the growth of its colonies in ring-like form sur- 

 rounding the crinoid columns to which they are attached. 



PALMACIS DBPRBSSU8 [Meet d Worth cm 

 Plate 10, figures 5-7 



1866. \ poi var. depressum M. ^ W.. Geological Survey of 



Illinois, volume 2. page 146. plate 14. figures 2a. 26. 



Desi — C rallum small, depressed, with a more or less truncate 



base: corallites one to four in number, with apertures usually nearly in 

 a plane. Substance of the corallum apparently perforated in all direc- 

 tions by meandering and anastomosing pores or fine canals. External 

 surface finely granular by reason of the presence of fine anastomosing 

 furrows which cover the entire surface. 



The dimensions of a corallum with three corallites is : Greatest width. 

 10 millimeters: height, 6,5 millimeters: diameter of corallites at aper- 

 tures. 4.5 millimeters. The corallites of dirTerent individuals van* in 

 width at their apertures from 3.5 millimeters to 5 millimeters. 



