155 



essential styliform columella. Septa arranged in a series of 

 deltas. Wall entire and with prominent granular costae. Pali 

 absent. No epitheca. 



The relations of the genus are with T)(dtocyathus, but 

 there are no pali. It is allied also to Turhinolia by its styli- 

 form columella, but departs from that genus by its shape, by 

 the arrangement of the septa, and by the absence of inter- 

 costal fossettes. 



Kionotrochus Suteri, spec. nov. PI. v., tigs. 5a, b. 



The numerous examples of this small coral are not quite 

 uniform in outline. The majority are short, and approxi- 

 mately hemispherical in shape, like the example figured, but 

 a few are slightly taller ; others again are low, almost discoid 

 forms. 



In adults the corallum is free, with a rounded convex 

 base, which shows a very small scar of former attachment 

 at its centre. Very young individuals are fixed generally to 

 shell fragments, and the corallum then has a flatly adherent 

 base and a perpendicular wall. The gradations from such 

 forms to those with a free rounded base is clearly traceable 

 amongst the smaller specimens. The scar of former attach- 

 ment becomes less and less conspicuous as the corallum in- 

 creases in size. 



The calice is circular and widely open. The septa are 

 exsert and in six systems, wdth three cycles. They are 

 slightly serrated at the margin, and their sides are beset wath 

 numerous strong, bluntly-pointed granules. The primaries 

 are longer and stouter than the secondaries, and these again 

 than the tertiaries. The latter curve round and join the sec- 

 ondaries near the columella, but so deejD down that in a fresh, 

 well-preserved specimen the junction is quite inconspicuous. 

 In worn examples, however, the deltoid combinations, form- 

 ed by the union of these septa, become w^ell marked. 



The columella is prominent, and in perfect specimens con- 

 sists of an irregular pillar, having buttress-like supports and 

 a central styliform projection. It is connected inferiorly 

 with the primary and secondary septa by slender processes; 

 in much-worn specimens the columella presents a fascicular 

 appearance. 



The costas are continuations of the septa, but are stouter. 

 They are highly granular, and form 24 equal, strongly-pro- 

 jecting ribs on the exterior of the corallum. The first two 

 orders continue to the centre of the base, near which the ter- 

 tiaries unite with the secondaries. In the intercostal spaces, 

 which are very narrow, the wall of the corallum is thin, 

 smooth, and entire. 



