PRESIDENT S ADDRESS — SECTION C. 



87 



pebbly bed containing more or less fragmental spec'mens of a 

 dark-coloured Osfrta, followed by a great thickness of sands, mud- 

 stones, marl and greensands, which in the Trelissick basin are 

 interstratified with basaltic volcanic ash, while doleritic sills appear 

 in the ccal meaures below (Speight, 1917, 1920). Dr. Marie Stopes 



Pre-Notocene. 



Pirlpauan. "Amupi limestone and' '"Grey marls" and" Greta beds.' 



Weka Pass stone. M'^unt Brown beds. Kowhai beds* 



^•^ Fig. 7. A diagrammatic section from North-west to Soutli-east across the Middle 

 Waipara Distrrict. (After Thomson, 1920.) 



(1914) has described as a new species of Araucarioxylon a petrified 

 stem in the basal beds at Amuri Bluff. In the calc'areous layers, 

 especially in the lower parts of this succession of sediments, there 

 have been found over fifty species of molluscs, the affinities of which 

 are clearly with these of the Indo-Pacific, Upper Senonian trans- 

 gression, the fauna being comparable with that of New Caledonia 

 (Piroutet, 1917), South Africa, Madagascar and Pondicherry 

 (Woods, 1917), but most markedly with that of Chili, Patagonia 

 and Seymour Island (Wilckens, 1920). Characteristic forms are 

 belemnites such as B. superstcs, amnfonites such as Kossmaticcr/is, 

 Ga>(dr?/ce7ns. Baciilites, and Hamites, Anisoceras ( ?), and lamelli- 

 branchs such as Tric/onia (especially T. hnnetiona), Pecten, Cal- 

 li>^ta, Ciicullftea, and Asfarte. 'irechmann's (1917b) study of the 

 gasteropods is in accord with this, the chief among the recognised 

 forms are Conchothyra, Pugnelliis, A po?-rhais, and a single Aus- 

 tralian form Natica var'ahilis. Further valuable information may 

 Be expected from Dr. Otto Wilcken's studies of the gasteropods, 

 which are now in the press. Among the greensands, there is a 

 zone containing many large coiicretions, often about bon^s of 

 saurians, of which PTector (1874) recognised a dozen species, chiefly 

 of the genera Lcindon and Chnoliosaurus. Dr. C. W. Andrews 

 {fide Woods, 1917) compares these with the reptilian fauna of the 

 Senonian Niobrara chalk of Nebraska, U.S.A. Chapman's (1918) 

 determinations of the fish teeth accord v?ith this correlation. Out of 

 the do'^en forms that he recognised, two only ascend into Tertiary 

 beds. This gro'up of formations of Senonian age, lying immediately 

 beneath tbe Amuri limestone, was referred to the Piripauan stage 

 bv Thomson (1916), followed by the Geological Survey (see Morgan, 

 1919): Marshall (1919). foll^-wpd by Soeight (1920), retains for it 

 Hutton's old name of the Waipara System, though as onginally 

 defined the latter contained also the Danian (?) Amur: limestone 

 above, and, perhaps, the Clarentian (Albian) beds alpo. 



