Prof. F. M'Coy on some new Silurian Radiata. 475 



apex, rarely exceeding that diameter, though occasionally 

 longer ; outer wall with faint vertical lamellar sulci, nine in 

 3 lines, at 9 lines in diameter, or about sixty-five all round : 

 horizontal section shows a dense, nearly solid, outer area less 

 than one-third the diameter of the tube, in which the radia- 

 ting lamellse and the excessively close fine vesicular connecting 

 plates are obscure ; an inner circular area about half the dia- 

 meter, into which only thirty-two to thirty-four (or each alter- 

 nate one) of the radiating lamellse penetrate, uniting irregu- 

 larly and slightly twisted about the centre, connected by very 

 few, thin, vesicular plates : vertical section, the nearly solid 

 outer area as above (about half an inch of the apex often also 

 filled with solid matter), inner area traversed by numerous de- 

 pressed small irregular cells, 'arranged almost horizontally, or 

 with a slight upward curvature. 



This species almost exactly resembles the small variety of the 

 Devonian Cyathophyllum ceratites of Goldfuss (which I also find 

 to be a Strephodes, thus differing from his larger variety to which 

 I restrict his name), but is readily separated by its closer and 

 more numerous lamellse (that having only thirty-seven lamellae 

 at the above diameter). The Streptoplasma corniculum (Hall), 

 from the Trenton limestone, is still more closely allied, but as it 

 is impossible to be certain of the species of those turbinated corals 

 without knowing their internal structure, I cannot venture to 

 unite our British species, which I have worked out, with the 

 American one, in which that has yet to be done, and of which I 

 have no specimens to do it. 



Common in the limestone of Old Radnor, Presteign, Radnor- 

 shire ; Wenlock limestone of Dudley, Staffordshire and Sedgley. 



[Col. University of Cambridge.) 



Strephodes trochiformis (M'Coy). 



Sp. Char. Corallum simple, slightly curved, widely turbinate, 

 average length 1 inch 3 lines, and width at mouth 1 inch 

 1 line, with irregular swellings of growth ; outer wall very thin, 

 marked with equal lamellar sulci (six in 3 lines at 1^ inch in 

 diameter, or eighty-three all round) ; terminal cup very deep, 

 conical, margin rounded, sides gradually sloping, lined by the 

 thin, alternately longer and shorter uneven-edged lamellae, the 

 longest of which are irregularly blended at the centre, con- 

 nected throughout by numerous curved transverse vesicular 

 plates : horizontal section shows the same characters as the 

 terminal cup, the alternate lamellse extending about half way 

 to the centre : vertical section, apex tilled with solid matter, 

 centre with irregular vermicular lines (the sections of the com- 



