316 THE PROCEEDINGS OF THE LINNEAN SOCIETY 



Genus Amphihelia, Edw. 8f H., 1849. 



Septa few, unequal ; no pali ; septal edges entire, slightly 

 exsert ; corallum dendroid ; corallites alternate ; columella rudi- 

 mentary ; costoe visible at the edge of the calice only. 



Amphihelia venusta, Edw. 8f H. 



Branches tending to develope on the same vertical plane ; 

 calices alternate : short costal grooves in the neighbourhood of 

 the calices, which are deep and without a columella ; septa in 

 three cycles, a little exsert, thickened exteriorly, a little bent, 

 unequal according to the orders, but sometimes in the same 

 order ; tertiaries rudimentary. Width of calices 3 millim. 



Not uncommon in many places on the east coast at moderate 

 depths, from 10 fathoms. 



Amphihelia incrustans, Duncan, Quart. Jour. Geol. Soc, 1870. 



Corallum flat, encrusting ; calices arising like crateriform pro- 

 cesses ; surface irregular, with undulating, subequal, bifurcating 

 costaa passing more or less obliquely to the outside of the calice ; 

 calices very minute, crateriform ; margins sharp ; fossa shallow ; 

 septa in six systems of three cycles with the rudiments of a 

 fourth, not exsert, and smaller than costae ; columella small and 

 projecting. 



Professor Duncan proposes to place the genus Amphihelia 

 amongst the Turbinolidse, because the calices do not fill up from 

 below, and the visceral chamber is quite free. It remains to be 

 seen if this arrangement will be accepted. With so highly 

 developed a coenenchyma, and a dendroid growth, the genus 

 would certainly be an anomalous one amongst the Turbinolidee, 

 while its connexion with other Oculinidas seems in all but the 

 absence of endotheca to be most natural. I have, however, in 

 my possession a fossil from Aldinga, in which some of the calices 

 on the same branch fill up from below, and some are quite empty 

 to the base of the fossa. This fossil will be figured and described 

 shortly. 



