332 Transactions.—Geology. 
Scaphula (?) lanceolata. 
Right valve. Shell small, thin, compressed, smooth, much elongated, 
not carinated behind, very inequilateral. Anterior portion short, rounded. 
Posterior portion elongated, gradually tapering, truncated at the end. 
Posterior dorsal margin straight. Hinge line straight posteriorly, curved 
anteriorly, edentulous in the centre. Eight anterior and eleven posterior 
teeth all nearly parallel to the hinge line. The three or four most anterior 
teeth are short, all the rest are elongated. From the umbo a narrow con- 
cave cartilage pit slopes very obliquely backwards, and divides the two sets 
of teeth. 
Length, -7 inch; height, ‘25 inch. 
Locality. Petane. Collected by Mr. A. Hamilton. 
Probably a new genus, as the shape is very different from the Indian 
shells and the posterior teeth are not branched. 
Mytilus striatus. : 
Shell elongated, inflated anteriorly, compressed posteriorly; finely 
radiately ridged and crossed by concentric rugose growth-marks. Umbo 
acute, terminal, compressed, strongly curved ventrally. Ventral margin 
slightly undulating ; dorsal margin rapidly rising from the umbo to about a 
third of the length, then parallel to the ventral margin; posterior end 
truncated. 
Length, 1:15 inch; height, :52 inch. 
Locality. Broken River. 
Art. XLL—On the Geological Structure of the Southern Alps of New 
Zealand, in the Provincial Districts of Canterbury and Westland. By 
Professor Junius von Haast, C.M.G., Pu.D., F.R.S. 
[Read before the Philosophical Institute of Canterbury, 27th November, 1884.] 
Tue publication of a new geological map of New Zealand accompanied by 
sections, issued by the Geological Survey Department, induces me to offer 
the following remarks on the geological structure of the Southern Alps, 
which I consider in some of its most essential features to have been alto- 
gether misunderstood by the officers of that survey. 
In my former publications I stated that the Southern Alps are only the 
eastern wing of a huge anticlinal arrangement, of which the western portion 
has been either destroyed or submerged below the Pacific Ocean. It thus 
exhibits the same one-sided features so conspicuous in almost every alpine 
chain of which the geological structure is known. 
