NIAGARA GROUP. 



113 



surface presents a variable character according to the degree of wearing which it has suffered? 

 and in the unweathered specimens the lamellae are not visible on the exterior ; and whenever 

 the lamellae become visible from weathering, they have a crenulate appearance. 



Fig. 2 a. An individual (larger than the prevailing size), somewhat weathered on the surface, 



and showing, slightly, the lamellae. 

 Fig. 2 />. A specimen of ordinary size, much weathered, and showing the lamellae in pairs and 



bifurcating above. 

 Fig. 2 c. A specimen showing two bases or points of attachment. 

 Fig. 2 (i. A specimen of ordinary size divided vertically, showing the depth of the cell, which is 



filled with fragments of corals. 

 Fig. 2 e. The cell of another individual, having the margin somewhat worn. 

 Fig. 2 /. Several of the lamellae enlarged, showing the termination of the alternate ones at the 



point where the cup deepens. 

 Fig. 2 §•. A transverse section near the base of a small specimen, showing the arrangement of 



the lamellae and the absence of transverse dissepiments. 

 Fig. 2 h. An individual of more elongated form than usual. The upper portion is a bud from 



one side of the centre of the lower cup, which the partial wearing down has made to 



appear as a continuation of the same. 

 vFig. 2 i. A longitudinal section showing a confused cellular structure below the centre of the cell. 



Position and locality. In the limestone of the group, a few feet above the shale, associated 

 with numerous species of corals, at Lockport. {State Collection.) 



419. 1. CANINIA BILATERALIS. 



PL. XXXII. Fig. 3 a, b, c. See Pl. 17, flg. 3. 

 This specimen was figured in this place before its true geological position was known. 

 This individual presents a better development of the characters of the species than those 

 from Reynale's basin, in which the cup is always more or less filled with extraneous matter, 

 and consequently the characters obscured. 



Fig. 3 a. View of the specimen, showing the cup with the depression in the dissepiment oa the 



anterior side. 

 Fig. 3 2i & 3 c, showing the arrangement and coalescing of the lamellae in the cup. 



Position and locality. From the siliceous portions of the limestone of the Clinton group at 



Lockport. {Collection of Col. Jewett) 



[ PaljEontologt — Vol. 11.] 15 "* 



