2 Mr. F. M'Coy on some new genera and species of 



in strength to the others as they approach the edge of the cup. 

 The denticulation of the lamellae is scarcely pei'ceptible. 



Not uucommon in the fine gray Devonian slates of New Quay. 



{Col. University of Cambridge.) 



Clisiophyllum Keyserlingii (M^Coy). 



Sp. Char. Conical, slightly curved, terminal cell oblique, 1 inch 

 2 lines in diameter in a specimen 3 inches long ; surface finely 

 striated longitudinally (about eight stria? in one-fourth of an 

 inch) ; lamellae thin, equal, about fifty-one, descending straight 

 into the deep part of the terminal star, and then abruptly 

 twisted spirally about an imaginary axis, forming a prominent 

 conical centre about one-third the diameter of the cup, and as 

 high as its base is wide. 



This highly typical species of Mr. Dana's American genus 

 Clisiophyllum is closely allied to the Cyathophyllum conisejitum of 

 Count Keyserling's ' Wissenschaftliche Beobachtungen aufeiner 

 Reise in das Petschora-Land,' from which it is distinguished by 

 the strong twisting of the plates about the central cone, and by 

 having little more than half the number of lamellae at the same 

 diameter. Viewing with Mr. Dana the conical arrangement of the 

 septa as a generic instead of a specific character, it seems probable 

 that the two varieties given by Count Keyserling of his Cyath. 

 coniseptum are really two species ; and the present species, though 

 presenting some intermediate characters, is I think distinct ; if 

 hereafter any one should think otherwise, they still could hardly 

 object to the name I have proposed in honour of so enterprising 

 a geologist, the more so as the term coniseptum would not be ap- 

 plicable as a specific name in the genus Clisiophyllu7n, where all 

 have the conical arrangement of septa alluded to ; there can how- 

 ever, I think, be little doubt of the distinctness of the species. In 

 the transverse section the central area seems a confused, close 

 crumpling of vesicular plates occupying rather more than one- 

 third the whole diameter, and from it to the circumference the 

 strong, equal, rather distant plates radiate. The external ver- 

 tical strijE are double the number of the actual radiating lamellae. 



Rare in the carboniferous limestone of Derbyshire. 



{Col. University of Cambridge.) 



Clisiophyllum hijmrtitum (M'Coy). 

 Sp. Char. Very elongate-conic, nearly cylindrical, with a dia- 

 meter of 1 1^ inch for the greater part of its length ; strongly 

 and regularly striated externally (about five striae in one-fourth 

 of an inch) ; external striae corresponding in number to the 

 radiating lamellae : in the transverse rough section the central 

 area is rather less than one- third the whole diameter, composed 

 of the edges of confusedly blended vesicular plates, crossed by 



