82 PALAEOZOIC CORALS AND FORAMINIFERA. 



In general appearance this resembles the L. duplicata (Mart, 

 sp.), but is much more rugose^ and the young branches expand 

 more rapidly ; in the vertical section it is distinguished by the 

 central line and the undefined sides of the axis^ as well as the very 

 much smaller size of the cells of tl^e vesicular structure, and the 

 much greater number of the radiating lamellae, which do not ex- 

 ceed twenty-four or twenty-six in that species. There is a slight 

 external resemblance between this coral and the Cyathophyllum 

 pseudo-vermiculare (M^Coy), but the prominent axis easily di- 

 stinguishes it. 



Common in the carboniferous limestone of Corwen. 



{Col. University of Cambridge.) 



Lonsdaleia ? stylastrcBafoi^mis (M^Coy) . 



Sp. Char. Corallum composed of easily separable (four- to six- 

 sided) prismatic tubes from 3 to 5 lines in diameter ; outer 

 walls faintly striated longitudinally, and marked with arched, 

 transverse, imbricating rugosities : vertical section, axis large, 

 defined, composed of irregular, spirally complicated lamellae ; 

 inner area of little- curved, vesicular plates, inclining obliquely 

 upwards and outwards, each plate generally extending from 

 the axis to the circumference of the inner zone, so that there 

 is but one, or occasionally two lengthened cells in a row be- 

 tween those points ; outer area narrow, composed of slightly 

 arched plates inclining obliquely upwards and outwards, each 

 plate usually reaching from the inner zone to the outer wall ; 

 more rarely a second arched plate is required, so that gene- 

 rally there is but a single row of long cells between the inner 

 zone and outer w^all, with occasionally a small irregular cell 

 towards the margin : transverse polished section showing a large 

 oval or circular, irregularly reticulated or cellular axis, from 

 which twenty-five lamellae of equal length and thickness ra- 

 diate almost to the outer walls, the cellular lining of the walls 

 free of radiating lamellae being very narrow, and forming ap- 

 parently a single row of irregular cells ; the spaces between 

 the radiating lamellae crossed by very thin arched plates : 

 transverse rough fracture generally cup-like above, the outer 

 zone forming an oblique, nearly uniform margin, faintly un- 

 dulated in a radiating direction, within which is the rough flat 

 fracture of the inner zone and axis; on the under side the po- 

 sition of those parts is reversed, the inner area being promi- 

 nent and surrounded by a narrow, radiated border sloping to 

 the walls. 



This coral is very remarkable for uniting in itself the internal 

 structure of Strombodes [Lithostrotion, Lonsd.) with the external 

 form and easily- separable columns of the Stylastrcea of the same 



