R. F. Tomes — British Cretaceous Madreporaria. 307 



a laro^e one and in fine preservation, with specimens of Leptophyllia 

 ■irregularis from Gosau, and find that, although it differs a little 

 from them in having rather thicker septa and costee, it corresponds 

 in every other particular, and so closely that the identity of the 

 species cannot be doubted. 



Stephanophyllia numismalis, sp. nov. Plate XIII, Figs. 5-8. 



The corallum is subcircular and much depressed, the upper 

 surface having but little convexity and the outer edge being very 

 thin. The base is a little concave. The basal wall is much 

 perforated, much more so than in StepJianophyllia BowerbanJct, 

 though less so thun in S. rndiata. The mural costge are rather 

 thicker than in S. BoiverbanTci, and not so closely placed, the perforated 

 spaces between them being nearly their own breadth. There are 

 about fifteen perforations between each pair of costfe, but the number 

 ns somewhat variable. The costse anastomose less freely than in 

 S. Bowerhanki, and there are no indications of dissepiments 

 between them. 



The columella is rudimentai'y and depressed. The primary septa 

 are straight, and pass into the columella ; they are relatively rather 

 thin and very irregular. The secondary septa are a little shorter 

 than the primary ones ; those forming the third cycle anastomose 

 with the secondary ones near the columella, and the septa of the 

 fourth cycle pass into those of tlie third at about half their length, 

 while the septa constituting the fifth cycle join those of the fourth at 

 a point approximately to their middle. There are some short and 

 very irregularly developed septa of the sixth cycle anastomosing 

 with the others. All the septa have margins which are excessively 

 rugged (lacerated is the word used by MM. Milne Edwards and 

 Haime), and the prominent angular points have the appearance of 

 being twisted or bent in different directions. 



Diameter of the corallum ... ... ... oi lines. 



Height of the corallum 1 line. 



One specimen only has been met with. It was obtained from the 

 zone of Actinocamnx quadrata in the Upper Chalk at East Harnham, 

 near Salisbury, and is in the museum of that city. I am indebted to 

 Dr. Blackmore for the opportunity of describing and figuring this 

 rare and interesting species. 



DESCEIPTION OF PLATE XIII. 



Leptophi/Uia irregularis, Eeuss, the corallum, natural size. 

 Ccelosmilia regularis, the corallum, natural size. 

 ,, ,, the calice, magnified twice. 



,, ,, a septum, magnified three times. 



Stephanophyllia numismalis, the corallum, natural size. 

 ,, ,, the same, seen in profile. 



,, ,, the calice, magnified three times. 



,, ,, a portion of the basal wall showing the inter- 



costal perforations, magnified three times. 



J'lG 



. 1. 





2. 





3. 





4. 





5. 





6. 





7. 



