Paleontology of (he Cincinnati Group. 201 



polygonal, separated by a moderate number of smaller inter- 

 stitial tubes, developed principally at the angles of junction 

 of corallites ; corallites in the center of the branches thin- 

 walled and polygonal, the walls becoming much thickened 

 as the tubes bend outward, and becoming amalgamated 

 with one another ; no spin i form tubuli ; tabulae always com- 

 plete and horizontal, well developed in all the corallites, and 

 throughout their whole extent ; small corallites much more 

 closely tabulate than the large ones. (Genus Montic, 1881, 

 p. 128.) {C/icctetes pulchelhis Nich., noii Edw. & Haime, 

 Quart. Jour. Geol. Soc. Lond., vol. 30, 1874, p. 503; Mono- 

 trypella csqualis Ulrich, Jour. Cin. vSoc. Nat. Hist., vol. 5, 1882, 

 p. 247.) 



Locality. — Cincinnati, O. 



Remarks. — As noted above, this species was originally 

 referred to as Chcctetcs pidchellus, although afterward described 

 as distinct. Monotrypella crqualis, placed here as a synonj'm, 

 seems to have but one character in which it differs from 

 ayidrewsi. This is in the absence of tabulae from the central 

 region of the branches. In order to compare the two forms 

 the following description is given : 



Monotrypella crqicalis Ulrich. Corallum irregularly ramose, 

 the branches cylindrical or compressed, two to five lines in 

 diameter ; surface often smooth, but sometimes with low, 

 rounded monticules, occupied by clusters of large cells g^- of 

 an inch in diameter; ordinary cells thin-walled, polygonal, 

 about ^X) inch in diameter ; a few cells slightly larger than 

 the average occasionally observed among the cells of the 

 monticules ; tangential sections show tubes to be regularly 

 polygonal, moderateh- thick-walled, and in contact with each 

 other on all sides ; the line of demarkation between the 

 tubes may be distinct or nearly wanting; walls thickened at 

 the angles, appearing like spiniform tubuli ; tabulae in the 

 axial region wanting or remote, but in the peripheral region 

 closely set or crowded, all straight or horizontal. 



30. — M. ULRiCHii Nicholson, 1881. 



Gorallum ramose, of cylindrical or sub-cylindrical branches, 

 dividing at irregular intervals, and from less than two lines 



