CORALS FROM THE LOWER CHALK. 53 



CHAPTER IV. 



CORALS FROM THE LOWER CHALK. 



The number of British Corals known to belong to this formation is as yet so very 

 small, that it would be premature to speculate on their mode of distribution. We have 

 seen but two species, one appertaining to the family of Oculinidae, the other to that 

 of Eupsammidse ; both appear to be peculiar to the lower chalk of England. 



Family OCULIXIDiE (p. xix). 



Genus Syxhelia (p. xx). 



Synhelia Sharpeana. Tab. IX, fig. 3, 3 a. 



Corallum composite, dendroid, with thick, erect branches, forming acute angles with 

 each other, and presenting on then surface large, non-exsert, circular calices, which are not 

 closely set, and are united by rather indistinct, small costal striae. Calices quite superficial, 

 and presenting scarcely any central depression. Columella assuming the appearance of a 

 small, obtuse tubercle. Three complete cycla of septa, and in one hah' of each system two 

 quaternary septa, of which no homologues exist in the other half. The septa are thick, 

 very closely set, almost straight, and unequally developed, but those of the second order 

 differ but little from the primary ones. The upper edge of all is horizontal, and closeJy 

 denticulated ; towards the columella the denticulations are rather larger than towards 

 the calicular margin, and we have not been able to decide whether some of them do 

 not constitute pali. The lateral surfaces of the septa present oblong transverse granu- 

 lations, which much resemble incomplete synapticulae, but they are not prominent enough 

 to meet those of the adjoining septa, and to subdivide the interseptal loculi. The height 

 of the specimen here described is about two inches and a half, and the diameter of the 

 calices two lines. 



We are as yet acquainted with but two other species that can be referred to our genus 

 Synhelia ; one is the S. (jibhosa, which was first described by Goldfuss under the name of 



