CORALS FROM THE INFERIOR OOLITE. 141 



3. Thamnastrea Mettensis. Tab. XXX, figs. 3, 3a. 



Corallum explanate ; its upper surface flat or slightly convex ; and its common basal 

 plate covered with an epitheca presenting concentric wrinkles. Calices superficial, rather 

 closely set, and forming, near the edge of the compound corallum, concentric series in each 

 of which the corallites are more approximated than in the contrary direction. Columella 

 rudimentary. Septa closely set, varying in thickness alternately, and not much genicu- 

 lated ; between sixteen and twenty-four round each fossula ; the tertiary ones often become 

 united to the secondary ones along their inner edge. Breadth of the calices two lines. 



Found in the Inferior Oolite at Crickley, near Cheltenham, by Dr. Wright ; and at 

 St. Quentin, near Metz, by M. Terquem. 



In this fossil the columella is quite rudimentary, and appears even to be quite deficient in 

 many of the corallites. T. Mettensis differs in that respect from most species of Tham- 

 nastrea, in which a papillose columella is usually visible in the centre of the calice. In 

 T. Defranciana^ the columella is also very obscurely defined, but the septa are thinner than 

 in the above-described species. 



4. Thamnastrea fungiformis. Tab. XXX, figs. 4, 4^a. 



Corallum, fungiform, pedunculate, and terminated by a convex surface. Calices some. 

 what unequal in size ; the largest rather prominent. 8e23ta about fifty in number, 

 somewhat unequally developed alternately, thin, closely set, and irregularly denticulated 

 at their upper edge. Breadth of the calices from two to three lines. 



Found in the Inferior OoUte at Charlcomb, by Mr. Walton. 



We have seen but a few ill-preserved specimens of this species, which appears to be 

 very nearly allied to T. arachnoides,^ but differs from it by its septa being more numerous 

 and more deeply denticulated. 



5. Thamnastrea M'Coyi. Tab. XXIX, figs. 2, la. 



We have not been able to refer to any known species this fossil, of which we have seen 

 but a single specimen in a very bad state of preservation, and much worn ; its walls are 

 polygonal, and circumscribed ; cahces of unequal size, in the centre of which a columella 

 appears to have existed. The septa, from twenty to twenty-four in number, are unequally 



1 Tab. xxix, fig. 3. - Tab. xxx, fig. 2. ^ Tab. xvii, fig. 1. 



