184 Cincinnati Society of Natural History. 



view of the presence here of interstitial tubes and spiniform 

 tubuli, both of which are absent from M. elcgans, to consider 

 it as a distinct species. It might, perhaps, be more correctly 

 referred to it as a variety. A new species, called by Mr. 

 Ulrich Diplotrypa patella, does not seem separable. Its char- 

 acters are as follows : 



Diplotrypa patella; Corallum lenticular, 25 to 38 mm. in 

 diameter and 2 to 4 mm. thick at the center; surface smooth, 

 the spiniform corallites projecting above the edges of the 

 calices; clusters of cells slightly larger than the average, but 

 not elevated above the general level ; under surface with a 

 thin and concentrically wrinkled epitheca ; corallites thin- 

 walled, eight in two mm., calices circular or polygonal, normal 

 ones .18 mm., but larger ones .25 mm. in diameter, arranged in 

 diagonally intersecting series; interspaces occupied by spini- 

 form corallites; tabulae moderately abundant, straight or 

 curved, especially in the lower part of the tube ; tabulae more 

 numerous in the small than in the large corallites. 



II. — M. CALYCULA (James) Nicholson, 1871. 



Corallum free, forming a thin, circular, concavo-convex 

 leaf-like expansion, ^V inch thick, one-half to two inches in 

 diameter ; under surface generally deeply concave, covered 

 with a thin epitheca, with fine radiating striae and a few con- 

 centric wrinkles; upper surface with oval or circular calices, 

 without monticules ; corallites of two kinds, larger oval, rarely 

 in contact, the smaller variable in size and shape, more or less 

 angular and wedged in between the larger ones; spiniform 

 corallites num-erous, thick-walled, mostly situated at points 

 where the larger calices should come into contact ; tabulae 

 wanting or incomplete (?) in the large, but numerous, closely 

 set, horizontal and complete in the smaller ones. (Cat. Foss. 

 Cin. Gr., 1871 (named). Ibid, 1875, p. i, as Chcetetesf calycula ; 

 Nicholson, Genus Montic, 1881, p. 165.) 



Locality. — Cincinnati, Ohio. 



Remarks. — This species is somewhat similar to the preced- 

 ing, but differs from it in having the edge of the corallum 

 thin, and sharp and often irregular instead of being regular 

 and thickened. Many specimens, are found with the cell- 



