60 . G. T. Trechmann — Age of the 



It is impossible to remove the hard rock to see if the large and 

 thick hinge-teeth and dental plates are present as they are in the 

 Australian equivalents of Spirifer glaber, and so the absolute identity 

 of the New Zealand with the Australian forms cannot be demonstrated. 



Waagen suggested that the Australian forms of Spirifer glaber 

 might belong to his genus Martiniopsis, 1 and this supposition is 

 followed by Etheridge 3 apparently on the strength of Waagen's 

 remai-ks. I am very doubtful whether these forms are sufficiently 

 akin to Waagen's Salt Range genus to justify us in calling them 

 Martiniopsis, in which the dental and septal plates are long and 

 narrow and do not seem to be accompanied by a shelly infilling of 

 the beak region. The ribbed Spirifers in the Australian Perrao- 

 Carboniferous and the New Zealand form of Spirifer bisttlcatus are 

 also similarly thickened in the beak of the ventral valve. Many 

 phyla of Brachiopods develop excess of shelly matter towards the end 

 of their existence, and it must be remembered that the Australian 

 Permo-Carboniferous marine bands are probably of Artinskian age 

 and very much younger than the English and Belgian Visean Lower 

 Carboniferous. 



Locality. — Maitai Limestone, junction of Wairoa and Boding 

 Eivers. 



Spirifer ■' cf. bisulcatus, J. Sow. (PI. V, Pigs. 1, 2.) 



Only one species of ribbed Spirifer seems to occur in the Maitai 

 Limestone, and in outward appearance it agrees with S. bisulcatus as 

 Hector originally identified it. It does not lend itself to a very 

 close comparison with any of Davidson's figures, but strongly resembles 

 an Australian specimen figured by de Koninck. 3 



The hinge-line is the greatest width of the shell. In the ventral 

 valve the median sinus is continued to the apex, and is broad and 

 shallow, and merges gradually into the rest of the shell. The ribs 

 are closely set, narrow, rounded, equally spaced, and are similarly 

 developed on the furrow as they are on the rest of the shell. I have 

 no specimens which show clearly the exterior of the dorsal valve. 



The interior of the ventral valve is much thickened posteriorly by 

 deposition of shelly matter, but the dorsal valve does not seem to be 

 thickened. The dental plates in the ventral valve are strong and 

 heavy, and the space between them and the area is much thickened. 

 The hinge-teeth correspond to wide and deep sockets in the dorsal 

 valve. The thickening of the ventral valve makes it appear that the 

 Australasian forms bear the same i-elation to the Northern S. bisulcatus 

 as the so-called Martiniopsis subradiata does to the European lower 

 Carboniferous Spirifer glaber, and that the similarity in exterior 

 ornamentation does not denote specific identity. 



Zaphrentis sp. (PI. IV, Pigs. 5-7.) 

 A selection of the few corals from the Maitai Limestone in the 

 collection of the New Zealand Survey was sent to Dr. A. Vaughan 



1 "Salt Range Fossils": 1, Productus Limestone Fossils: Pal. Ind., 

 ser. xni, vol. iv, fasc. 2, p. 525, 188 5. 



2 PalcBontology and Geology of Queensland, 1892, p. 237. 



3 Palmozoic Fossils of Neiv South Wales, pi. xiv, fig. 5c. 



