Maitai Series of New Zealand. 61 



some years ago. No report on them has appeared, and as a result of 

 his death the specimens cannot now apparently be traced. However, 

 1 found a specimen still remaining in the collection, Dr. Thomson 

 found another in the Maitai Limestone, and I collected a third quite 

 satisfactorily preserved specimen showing the sharp rim of the calyx 

 and other features. All that I have seen are forms of Zaphrentis. 



The specimen I collected (Kig. 7) must have measured about 

 55 mm. in length. The breadth at the top was about 25 mm. and the 

 depth of the calyx 16 mm. The corallum is turbinate and almost 

 circular in section, and the edges of the calyx are sharp. A section 

 made slightly below the calyx shows that the fossula reaches slightly 

 beyond the centre, and there are about forty-two septa, which are 

 slightly sinuous and do not all reach the centre. The septa are 

 about equally thick and maintain this thickness in their whole length. 

 The outer ends fuse to form a quite thick thecal wall. The fossula 

 is divided by a septum to about half its length from the outer wall. 

 Three or four thin irregularly spaced dissepiments are seen joining 

 each pair of septa. 



This coral rather resembles Z. Gregoryana, deKon., 1 which occurs in 

 the Permo-Carboniferous of Jervis Bay, N.S.W., but in that form the 

 septa number thirty-six and are stated to be thicker at the outside 

 than at the inside. 



Another coral (Figs. 5, 6) is more oval in section. The septa 

 number about 68 or 70, and are irregularly sinuous and wavy and 

 are more or less regularly and alternately thick and thin. The 

 septa all reach the fossula, which extends to slightly beyond the 

 centre, and is divided along its whole length by a thin median 

 septum, with a shorter but equally thin lateral septum on either side. 

 The septal ends fuse to form a fairly thick outer Avail, which, 

 however, is partly eroded. 



Locality. — Both these corals occurred in the Maitai Limestone at 

 the junction of the Waiioa and lloding Rivers. 



[Since writing the above I have received the following note on 

 the coral sections from Mr. Stanley Smith, D.Sc, F.G.S., who- 

 has kindly examined the specimens for me : — "Both specimens may 

 be safely assigned to the genus Zaphrentis, although it would not 

 be wise to compare them with any British species, especially since 

 they have undergone considerable mineral change. The specimens 

 appear to represent two distinct species rather than two growth 

 stages of a single species. The larger specimen (Fig. 7) displays 

 a large and conspicuous cardinal fossula, the septa are not crowded, 

 and there is a well-developed dissepimental zone. In the smaller 

 specimen (Fig. 5) the fossula is distinct but not prominent, the septa 

 are numerous and crowded, and there is no dissepimental zone. 

 The latter may have perished or may be undeveloped at the stage 

 growth represented by the section. In the two sections only the 

 major septa are developed ; in Fig. 5 the septa are dilated and split 

 by mineralization, so that the first impression is thut of thin septa 

 alternately long and short ; the shorter line is the medial ' dark 

 line' of the septa."— S. S.] 



1 Palceozoic Fossils of New South Wales, pi. v, fig. 7. 



