108 



base concave, and very slightly smaller than calice. Costae, very pro- 

 minent, continuous with septa, not quite so wide as intercostal spaces, 

 smooth, acute, persistent to the centre of base. Epitheca, none. Calice, 

 circular. Xossa, very sLallow, scarcely depressed in the centre. Systems, 

 six. Cycles, four. Septa, not exsert, or only slightly. Pali, apparently 

 before secondaries, a chevron-like mass with the ends directed towards 

 tertiary septa. In the specimens the surface is worn, and the pali are 

 indistinguishable from the septa, and it thus appears as if the tertiaries 

 united with the secondaries about a third from centre. There are also 

 tubercles in the centre which seem like pali of primaries. Wa<l, thin, 

 bending outwards to meet costa. Dimensions — Alt., \\ ; diam. 3 

 millim. 



Only two specimens, both worn, and one a little broken ; the 

 latter the only one in which the pali could be fairly made out. Better 

 specimens may however show that some of my conclusions are subject to 

 modification. It is closely allied to the living D. rotaeformis, nobis, but 

 in that species the costae do not correspond with the septa. I have great 

 pleasure in dedicatiHg this species to my friend Prof. Tate, whose zeal 

 and industry in the cause of geology need no encomium from me. It 

 should be noted that the concavity of the base is not seen except in the 

 longer specimen, the other being convex. In the young stages of 

 Deltocyathus italicus the base is often rounded, and in form like Trocho- 

 cyathus meridionalis, Duncan ; but in all other respects the species seem 

 to be different. 



Deltocyathus alattjs, n. sp., pi. 2, fig. 4. 



I am doubtful whether to regard this fossil as only a variety of D. 

 exoisux, Duncan. It comes from the Murray cliffs where the latter is 

 not found. Its peculiarities are as follows. The septa are much more 

 spinous in their granules, and they are not so exsert but often deeply 

 lobed. That is to say the kind of lobate teeth and crest at the edge of 

 the primaries and secondaries are distinctly divided and stand out 

 separately. The pali are very solid and distinct. There is no columella, 

 but the septa and pali unite in the centre. The two prolongations of 

 costae at each side of the coral in D. incisus become flattened and spread 

 out into aliform appendages in this coral. Not, however, in all cases. 

 There are specimens which approximate closely to D. incisus; and there 

 are others where they are much more prominent, and more spread out on 

 the side of the corallum than in the figure given. The granules on the 



