282 Prof. F. M'Coy on some new genera 



35 to 100, marked with very strong concentric undulations ; 

 .j:. radiating ridges very numerous, straight, slender, simple, of 

 iij unequal lengths, averaging with considerable regularity half 



a line apart; intervening spaces finely striated radiatingly; 



long diameter varying from 7 lines to 1 inch 3 lines. 



.i\ This species is easily distinguished from the S. Edwardsi 

 (Murch.) by having considerably more than double the number 

 of radiating ridges ; they have never been seen to dichotomize, 

 but retain their comparatively near approximation by the inter- 

 calation of similar, straight, shorter ridges towards the circum- 

 ference ; the substance also appears stronger and is more strongly 

 wrinkled concentrically; the small radiating striee between the 

 larger ridges are very characteristic. 



One very obscure specimen, apparently of this species, measures 

 2 inches in its long diameter ; the distance between the main 

 ridges is about four times their thickness. 



H Abundant in the green micaceous quartzite of the Upper Lud- 

 low at Benson Knot, Brigsteer and Scalthwaiterigg, Kendal. 



ti^'doid^'m ^Pongarium interruptum (M^Coy). .,;^'^ f^,^^ 



Sp. Char, Elliptical, proportion of width to length about 85 to 

 100, convex below or externally, concave above or internally ; 

 interior smooth, or marked with faint concentric wrinkles; 

 exterior rugged with coarse concentric undulations, entire 

 outer surface marked with sharp, subalternate, thread-like 

 striae, five or six in one line ; some of which rise at irregular 

 intervals into short, very thick, subangular, radiating ridges 



J,,,, interrupted by the concentric wrinkles and not regularly re- 



^^^.sumed. Average length 1 inch. 



oi-iThe sharp alternately large and small striae, and the short 

 ilTegular interrupted ridges or elongate tubercles produced by 

 the irregular prominence of some of the ridges, distinguish this 

 species readily from the others. Two of the specimens are of 

 great interest, one showing the attachment of the base half round 

 a bit apparently of an Orthoceratite , the other showing for the 

 first time the thickness of the substance to be about one-sixth of 

 a line, and exhibiting the unradiated inner concave surface, and 

 the impression of a part of the peculiarly radiated exterior. 



Rare in the green micaceous quartzite (Upper Ludlow) of 

 Spital, Kendal. 



Nebulipora (M'Coy), n. g. 



Gen. Char. Corallum incrusting or forming lenticular masses, 

 with a concentrically wrinkled epitheca below; composed of 

 small prismatic tubes perpendicular or nearly so to the upper 

 surface on which they open ; among the small tubes are irre- 



