MESOZOIC RADIATA. 49 



This fine species is abundant in tlic lower oolite, and seems to 

 be constantly distinguished from the A. helianthoicbs (Gold.) of 

 the coralline oolite by its smaller and more equal cells, more nu- 

 merous lamellae and flatness of the masses, particularly of the 

 stelliferous surface. 



Common in the inferior oolite of Dundry. 



[CoL University of Cambridge.) 



Siderastrcsa agariciaformis (M'Coy). 



Sp. Char. Corallum forming large foliaceous expansions; cells 

 about 1|- line in diameter, arranged in rows, the cells of each 

 row half their diameter apart, the rows nearly twice their dia- 

 meter apart ; the cells are radiated by about twelve lamellae 

 from a depressed cellulose centre ; they increase in number 

 towards the margin, and the greater number take a straight 

 course in two opposite directions to unite with the nearest star 

 of the adjoining row on each side (giving the corallum the 

 appearance of being strongly striated in one direction as in 

 Agaricid), 



This coral is very like the lower part (natural size) of Gold- 

 fuss's figure of his Astr(2a fiexuosa from the cretaceous rocks of 

 St, Peter's Mountain, It is most usual to find the lower side 

 exposed by a sort of rough section, in which the cells project like 

 the so-called genus Montastrcea. In the section the small con- 

 necting vesicular plates are seen. 



Common in the coral rag of Upware, near Cambridge. 



{CoL University of Cambridge.) 



Meandrina vermicularis (M'Coy). 

 Sp. Char. Corallum forming depressed rounded masses 3 or 4 

 inches in diameter; upper surface covered with vermicular 

 contorted ridges about half a line in diameter, from 1 to 2 

 lines apart, and about 1 line high, variously connected at in- 

 tervals, their sides very finely and regularly striated by the 

 minute lamellse (about eight or nine in the space of one line), 

 and a single row of little stars in the valleys between each pair 

 of ridges. 



The extreme slenderness of the ridges and their strong con- 

 tortion give this coral the appearance of a mass of little marine 

 worms, and separate it easily from all known species ; it far ex- 

 ceeding the M. venustula (Mich.) and M, Lotharinga (Mich.) in 

 those respects, and I know no other species to which it makes 

 any approach. 



Rare in the inferior oolite of Leckhampton. 

 {Col. University of Cambridge.) 



