INDIANA PALEONTOLOGY. so. 



MONILOPORA BEECHERI Grabau 



Plate 19. Figs. 20, 21. 

 Monilopora beeeheri, Grabau — (1899, Proe. Bost. Soc. Nat. Hist. voL 28, p. 411, pL I, figs. 2-3, 



and pL 2, figs. 1-5.) 



Corallum regularly branching or forming a confused mass of intergrown 

 tubes, which branch and repeatedly unite; the calices opening in all directions. 

 Tubes expanding rapidly towards the calyx, below which they give olf one or 

 more lateral buds. Adjoining corallites frequently united by their walls. 



Walls thick, especially in the lower portions of the corallite, consisting of 

 numerous concentric lamellse. These at intervals are separated so as to leave 

 sub-equal lacuna?, which are traversed by numerous fine transverse bars or 

 trabeculse, rather irregularly disposed. 



Visceral chamber of corallites open throughout, as in all the species of this 

 genus. Corallites connected with their parent basally, except in old individu- 

 als where they have become constricted off, and the pores covered by a layer of 

 sclerenchyma. 



Observations. — In the two specimens figured there is a total absence of 

 regularity of budding, the calices opening in all directions, and the individuals 

 freely uniting. This indicates that the specimens were supported. 



Specimen figure 21 is attached to one side of a crushed calyx and arms of 

 Platycrinus (not drawn in the figure), but it is impossible to determine 

 whether this attachment was accomplished before or after the death of the 

 crinoid. The latter was probably the case. 



Faint septal ridges are shown in a number of specimens, in some becoming 

 quite strongly marked, and rather broad. 



Specimen figure 20, probably encircled a crinoid stem, but the other speci- 

 men figured is too massive and seems to have grown in a suspended manner. 

 Colonies encircling crinoid stems are not at all uncommon. Many merely sur- 

 round the stem without seeming to affect it in any way, and in such cases the 

 calices open in all directions. Others, however, have become imbedded in the 

 substance of the crinoid stem, which has become enlarged, as is the case so 

 generally with the European M. crassa. In some specimens observed, the 

 crinoid stem has grown to such an extent as to completely bury the coral in 

 its substance, only the calices remaining slightly raised above the surface of 

 the stem. In such cases aside from the enlargement there seems to be no mod- 

 ification of the characters of the stem. 



In a well preserved specimen from Edwardsville, Indiana, fine thread-like, 

 but prominent, and slightly wavy encircling strise were seen covering the cor- 



