154 



The columella occupies much space, and consists of nume- 

 rous papilli, which, though irregular in shape, are on the 

 whole more rounded than the pali. 



The costae correspond to the septa, and are formed of 

 closely-packed, flattened granules, bearing horizontal spines 

 which project into the narrow intercostal spaces. They descend 

 perpendicularly on the wall, until they bend round with the 

 curvature of the inferior portion of the corallum. The prin- 

 cipal costas are slightly larger than those of higher order. The 

 latter sometimes unite on the wall, and then continue to the 

 extremity of the base as a single broad costa, or all three 

 of those lying between the principal costse may broaden out 

 independently. The specimens show considerable variation 

 in the arrangement of the costse on the basal portion of the 

 corallum. The base itself is peculiar. It really extends from 

 the commencement of the convex curve of the corallum, and 

 is formed of three or four costae, which are much broader than 

 any of those on the wall proper. There is no epitheca. 



Height of corallum, 4'5 mm. ; diameter of calice, 4 mm. 

 The coralla are not quite uniform in shape, the curvature be- 

 ing occasionally less than in the type, while the base again 

 may be more sharply pointed. 



Dredged by Messrs. Hedley and Petterd 20 miles north- 

 east of Port Jackson, at a depth of 250 fathoms. Nine speci- 

 mens were obtained, of which the type is perfect, and the 

 others in tolerable order. 



Genus Deltocyathus, Milne-Edwards and Hainie. 



Deltocyathus rotaeformis, Tenison Woods, Linn. See. 

 N.S.W., vol. II., pp. 306-7, pi. v., fig. 2. 



The description and drawings of this coral given by 

 Tenison Woods are correct. His examples, six in number, 

 were dredged off Port Stephens by the late W. Macleay, at 

 a depth of 71 fathoms. After the lapse of many years, it 

 has now been dredged by Messrs. Hedley and Petterd, at 250 

 fathoms, 20 miles north-east of Port Jackson (11 examples); 

 and also by Dr. Verco, at 104 fathoms, 35 miles south-west 

 of Neptune Island, South Australia (147 examples). The 

 latter gentleman also found the coral in considerable num- 

 bers and at varying depths, up to 200 fathoms, off Cape Jaffa 

 and Beachport. Two of the New South Wales specimens 

 are slightly larger than any from South Australia. 



The alternation of the costoe with the septa is a remark- 

 able feature of the species, and serves to distinguish it from 

 all others in the genus. 



Genus Ktonotrochus, nov. 

 A Turbinolian coral, having a rounded free base, and an 



