38 



the other, the younger upon the older. As the direction of the new cups does not always 

 accord with that of the old ones, the general form produced by this mode of increase is often 

 very peculiar and irregular. Some specimens also show extraordinary lateral prolongations of 

 the epitheca. 



In many respects, C. vesiculosum resembles C. Senecaense and G. grande, but it is on an 

 average larger than the former and smaller than the latter. It is also distinguished by its 

 mode of increase, the disposition of its cells, its very deep calice, and its surface-characters. 

 From G. Americanum it is distinguished by its larger size, more turbinate form, larger 

 calice, and wrinkled epitheca. 



Locality and Formation. Hare in the Corniferous Limestone of Port Colborne and 

 Hagersville. Very abundant in the Hamilton Formation of Bartlett's Mills, near Arkona, 

 Township of Bosanquet. 



35. CYSTIPHYLLUM SULCATDM (Billings). 

 (Plate VI. Fig. 7). 



Cystiphyllum sulcatum (Billings), Canadian Journal, New Series, Vol. IV. p. 136. 



" Corallnin simple, short, turbinate, much curved, expanding at the rate of between forty 

 and forty-five degrees from the minute sharp curved point upwards ; cup oblique, the lower 

 margin being on the side of the lesser curvature, moderately deep, and nearly regularly con- 

 cave, the bottom covered with obscure coarse rounded radiating ridges ; a shallow rounded 

 groove or fossette extending from the centre to the higher margin, and in some specimens two 

 others much less distinct, radiating to the sides at right angles to the main groove. Exterior 

 encircled by obscure undulations, and longitudinally striated by the rudimentary radiating 

 septa. The vesicular structure consists of irregular sub lenticular cells, from half a line to two 

 lines in width ; length of the convex side, from one inch and a half to three inches ; the usual 

 length appears to be about two inches or a little more ; width of cup from one inch to one inch 

 and a half ; depth about half an inch" (Billings). 



This pretty little species, in its external appearance, presents a close resemblance at first 

 sight to small specimens of Zaphrentis prolifica (Billings,) from which, of course, its internal 

 structure separates it at once. The epitheca is tolerably thick, and exhibits with unusual 

 distinctness the vertical ridges which mark the position of the septa, along with numerous 

 rounded annulations and folds of growth, these latter being sometimes obscure. G. sulcatum 

 can readily be distinguished from all other species of the genus by its general form, its surface- 

 characters, the great obliquity of the calice and the fossular furrow. 



Locality and Formation. Corniferous Limestone, Rama's Farm, Port Colborne. 



Genus MICROCYCLUS (Meek and Worthen). 



" Corallum free or with a minute central point of attachment, discoidal, without colum- 

 ella ; calice very shallow or nearly obsolete, and provided with a single small fossette ; septa 

 short, nearly regularly radiating, or with a few of those nearest the fossette converging a little 

 towards its sides ; epitheca well developed. 



" This little coral seems to be nearly related to Combophyllum and Baryphyllwn, (Ed 

 wards and Haime), but differs from the first in having a well-developed epitheca, and from the 

 latter, not only in that character, but in having its fossette simple, and its costse nearly regu- 

 larly radiating. It also presents similar differences from Hadropliyttum of Edwards and 

 Haime." (Meek and Worthen, Geology of Illinois, Vol. III. p. 420). 



36. MICROCYCLUS DISCUS. (Meek and Worthen). 



Microcy civs discus. (Meek and Worthen,) Geol. of Illinois, Vol. III. p. 420, PI. XL 

 Fig. 7, a. I. 



" Corallum depressed-discoid ; periphery sharp, under side flat, and protected by the 

 concentrically-wrinkled epitheca ; upper side slightly convex, flat or a little concave in the 

 middle ; fossette small, shallow, and extending from the centre to the margin. Septa very 



