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



usually slightly less than half a line in diameter^ and avera- 

 ging rather less than their diameter in the shortest line between 

 adjacent cells, in which line there are usually two, or more 

 rarely three, of the intermediate vesicular cellules ; about 

 eighteen of the intermediate or polygonal cellules in the space 

 of 2 lines ; diaphragms in the small tubes slightly more or 

 less than their diameter apart, two interdiaphragmal spaces 

 in the large tubes slightly exceeding the diameter. 



So exactly does this resemble the Palaopora interstincta (Wahl.), 

 that I have little doubt it has often been confounded with it, 

 although an attentive examination will show that the distinctly 

 walled tubes are smooth within and perfectly destitute of lamellae. 

 I have seen this coral also in large masses in the Upper Silu- 

 I'ian limestone of Gothland. It may be distinguished from the 

 very nearly allied Manon [Fistulipora) cribrosa (Gold, sp.), by 

 the smaller size of the cell-tubes and their greater number in 

 a given space, their proportionate distance being pretty nearly 

 the same. In both the British and foreign specimens the cells 

 are so beautifully distinct, that it would be impossible to over- 

 look the notches or rudimentary lamellae if they existed. 



Forming large masses not uncommonly in the Wenlock lime- 

 stone near Aymestry. 



Berenicea heterogyra (M'Coy). 



Sp. Char. Parasitic, often on Orthoceratites, covering spaces of 

 upwards of 2 inches square; cells disposed in irregular radiating, 

 or divaricating, circular, or fan-shaped lines, ten or eleven oc- 

 cupying the space of 1 line (measured across their length), and 

 about three in the same space in the direction of their length, 

 each cell slightly more than the third of a line long, very nar- 

 row, fusiform, about four times longer than wide, and sepa- 

 rated by a space, varying from their greatest width to less than 

 one half their width or nearly in contact ; upper convex sur- 

 face of each cell with four or five large tubercles when well 

 preserved. 

 The cells of this remarkable species are almost invisible to the 



naked eye, but it occurs forming patches of considerable size ; 



the small size of the cells and their very elongate slender form 



distinguish this species from the B. irregularis of Lonsdale. 

 Coniston limestone of Coniston. 



POLYZOA. 



Ptilodictya explanata (M'Coy). 

 Sp. Char. Corallum forming large funnel-shaped foliaceous 

 flexible expansions upwards of 2 inches wide ; axis semimem- 



