Paleoutology of the Ciuciniiati C.roufy. 157 



(iROUP I. — Massive: Free, or attached at one point or by 

 the whole of the base ; more or less spheriodal, globose or 

 massive. 



a. Surface smooth ; coralluiu massive 1 



Corallum free, spheriodal 2 



h. Surface not smooth ; massive, with monticules 3 



Spheriodal, nodulated 4 



I. — M. UNDULATA, Nicholson, 1S75. 



Corallnni forming large, lobed or laterally indented masses, 

 with a maximum diameter of four inches and a height of 

 about two inches, the upper stirface nearly flat ; corallites 

 thin walled, angtilar and prismatic ; calices sub-equal, with 

 occasional clusters of six or more, forming small patches, 

 which are faintly or not at all raised above the general sur- 

 face; small corallites sometimes present at the angles of junc- 

 tion of the larger tubes ; tabulae few, complete, placed at 

 corresponding levels in contiguous tubes. (CtCoI. Mag., decade 

 2, vol. 2, 1875, p. 176.) 



Locality. — Ontario. 



Remarks. — This form, as far as at present known, has only 

 been found in the Trenton of Canada. A small hemispherical 

 or spheroidal form occurring in the Cincinnati Group has 

 been placed here b)' Dr. Nicholson, wuthotit a special name. 

 This is described below under a varietal name. The above 

 description is given so that the species may be recognized in 

 case it be found in our region. 



var. iiKMiSPHERiCA, n. var. 



Fig. \o.—MoTiticulipora undnlata, var. hemispherica, n. var. a coraHum, nat. 

 size ; b tangential section x 18; f longitudinal section x 18. (After Nicholson.) 



