38 BRITISH FOSSIL CORALS. 



slender, closely set, projecting very little, equal, sub-vermiculate, and assuming the 

 appearance of vertical strise irregularly broken at short distances, but not distinctly 

 composed of granulations, as is the case in most Eupsammidse (fig. 4 a). Walls perforated, 

 as usual in this family, near the calice, but becoming compact lower down. Calices 

 circular, infundibuliform, rather deep, and having an obtuse edge. Columella quite 

 rudimentary, or not existing at all. Four septal cycla, the last of which is quite 

 rudimentary, whereas the others are well developed proportion ably to their age. The septa 

 are very thin, closely set, not remarkably exsert, terminated by an oblique, nearly entire 

 edge, and proceed in a straight direction towards the axis of the corallum, but present an 

 undulate appearance, due principally to the existence of a few large lateral granulse. The 

 six systems are equally developed, and very distinct ; the primary and secondary septa 

 meet along their inner edge in the middle of the visceral chamber. Height of the 

 corallites, about two or three lines ; diameter of the calices, about two thirds of a line. 



This fossil, of which we have seen but one specimen, that was found at Bracklesham Bay, 

 and belongs to the cabinet of Mr. Frederick Edwards, is the only known species of the genus 

 Stereopsammia. The regular radiate structure of its calice distinguishes it from most of 

 the Bupsammidse, and in the genus Ccenopsammia, where the same character is met with, 

 the columella is essential and well developed, 1 whereas in Stereopsammia it does not exist, 

 or is quite rudimentary. 



Family PCRITIDJE (p. lv). 



Tribe PORITINiE (p. lv). 



1. Genus Litharge a (p. lv). 

 Litiiar/ea Websteri. Tab. VII, figs. 1, 1 a, 1 b, 1 c. 



Astrea Websteri, J. 5. Bowerbank, on the London Clay Formation, in Charles-worth's 



Mag. of Nat. Hist., new series, vol. iv, p. 23, figs, a, b, 1840. 



Siderastrea Webstert, Lonsdale, in Mr. Dixon'? unpublished work on the Chalk Forma- 

 tions and Tertiary Depo^ta of Sussex. 



Corallum composite, incrusting, adhering in general to large pebbles, and forming a 

 thick convex mass, on the edge of which some traces of a rudimentary epitheca are 

 sometimes perceptible. Multiplication by gemmation in the spaces comprised between the 

 calices. Corallites sometimes united by a spongy coenencliyma ; in other parts crowded 

 together so as to render the calices. almost polygonal, and separated only by a thin, simple, 

 common margin. Calices infundibuliform, but not deep. Columella well developed, 



1 Annales des Sc. Nat., 3 me serie r vol. x, tab. i, figs. 11, 12. 



