170 SILURIAN llADIATA. 



Not very uncommon coating Orthoceratites in the Upper Lud- 

 low rock of Brigsteer, and Coniston flags of Coniston, also at 

 Firbank. 



{Col. University of Cambridge.) 



Favosifes crassa (M^Coy). 



Sp. Char. Corallum forming large, subcylindrical, curved 

 branches, composed of long, slightly diverging, remarkably 

 regular and equal prismatic tubes, opening as thin-walled 

 polygonal cells on the surface, with a nearly uniform diameter 

 of half a line ; two rows of pores on each face of the prismatic 

 tubes, diaphragms either slightly more or less than the dia- 

 meter of the tubes apart ; interpolated young tubes few. 



In the general characters of the tubes and connecting foramina 

 this species nearly agrees with F. Gothlandica, from which spe- 

 cies it is distinguished by the elongate branch-like form of the 

 general mass, the tubes averaging rather less than half the dia- 

 meter, and being far more uniform in size than in that species, 

 from the small number of interpolated young tubes, connected 

 probably with the shape of the corallum, which is elongated instead 

 of forming low wide masses as in F. Gothlandica. I suspect this to 

 be the coral occasionally quoted as the Devonian F. polym^orpha 

 in Silurian rocks, a species which is very distinct from the pre- 

 sent, and which I have never seen in Silurian strata, nor seen 

 any recognizable figure of a Silurian specimen. As the essential 

 characters are neither described nor figured, I do not like to refer 

 to the figure (t. 15. f. 2) of the so-called F. polymorpha given 

 by Mr. Lonsdale in the ^ Sil. Syst.,^ placed in the genus Alveolites 

 by M. D^Orbigny under the name (without definition) of A. 

 Lonsdalii, although the size of the tubes coincides. 



Masses 2 inches in diameter and 6 inches long in the Coniston 

 limestone, Coniston Water. 



{Col. University of Cambridge.) 



Coenites strigatus (M'Coy). 



Sp. Char. Corallum forming cylindrical, dichotomous branches, 

 2 to 3 lines in diameter ; surface with small, narrow, trian- 

 gular cells, the base of the triangle below, and the apex usually 

 more or less prolonged upwards into a vermiform channel, 

 often upwards of half a line long ; four to five rows of cells in 

 the space of 1 line, measured transversely, about two in the 

 same space measured longitudinally ; compact interstitial space 

 between the rows of cell-openings usually rather exceeding 

 their width. 



The usual compact appearance of the Coenites, combined in this 

 species with the interrupted scratch-like channels of the cell- 



