'39 



CHAPTER V. 



GENERA OF FAVOSITID^; (continued). 



Genus MICHELINIA, De Koninck, 1842. 

 (An. foss. des terr. Garb, de le Belgique, p. 29.) 



Gen. Char. Corallum forming hemispherical, depressed, or 

 pyriform masses, often of considerable size, composed of pris- 

 matic or subcylindrical corallites, in close contact throughout 

 their entire length. Walls not thickened to any unusual extent, 

 perforated by numerous mural pores, which are often multi- 

 serial, and have no definite arrangement. Calices polygonal or 

 subcylindrical, not surrounded by thickened margins. Tabulae 

 numerous, generally more or less curved with their convexities 

 upwards ; usually anastomosing with one another to a greater 

 or less extent, so as to give rise to a loose and open vesicular 

 tissue; and often carrying numerous vertically-directed spin- 

 ules. Septa represented by numerous radiately - arranged 

 longitudinal striae, ridges, or vertical rows of tubercles, varying 

 in number from twenty-five to forty. Under surface covered 

 by a concentrically-striated epitheca, which may or may not be 

 provided with hollow radiciform prolongations. 



Obs. This well - known genus comprises a number of 

 Devonian and Carboniferous corals, which present a close 

 general resemblance to the larger forms of Favosites. The 

 corallum (fig. 21) is massive, usually more or less hemispheri- 



