CORALS FROM THE UPPER GREENSAND. 57 



CHAPTER V. 



CORALS FROM THE UPPER GREENSAND. 



The class of Polypi had not, in all probability, numerous representatives in the seas 

 where the Upper Green Sand was deposited, for we have as yet seen only four British 

 species belonging to that formation, and the English geologists do not appear to have met 

 with many more. Most of these fossils belong to the family of Astreidee, and have been 

 found at Haldon, at Blackdown, or at Warminster. One of these British species 

 appears to be identical with a coral described by Goldfuss, and found in the chalk forma- 

 tion of Essen ; and Mr. Morris has pointed out two others as being referable to species 

 found in the chalk of Maestricht, but we have not had an opportunity of recognising the 

 specific identity of these last-mentioned fossils. 



Eamily ASTREID^ (p. xxiii). 



Tribe EUSMILIN^ (p. xxiii). 



1. Genus Peplosmilia (p. xxv). 



Peplosmilia Austeni. Tab. X, fig. 1, 1 a, 1 b. 



Corallum simple, fixed by a broad basis, cylindrical, and surrounded from top to 

 bottom by a membraniform epitheca, presenting some slight transverse folds. Calice 

 circular, or somewhat oval ; fossula shallow, narrow, and elongated. Columella well 

 developed and lamellar. Septa appearing to form four well-developed cycla, and a fourth 

 rudimentary one. The primary and secondary ones equal, and differing but little from 

 the tertiary ones ; they are all thick, broad, closely set, slightly exsert, not quite straight, 

 those on one side inclining to the right near the columella, and those of the other side 

 bending in an opposite direction. A vertical section of this Coral (fig. 1 b) shows that 

 the septa are granulated on their lateral surfaces, especially near their inner edge, which 

 joins the columella, and that these granulations form closely-set radiate rows. Dissepi- 

 ments vesicular, and rather abundant. Height of the coral, one inch and a half; diameter 

 of the calice, above an inch. 



