part 3] THE TRIAS OF KEW ZEALAND. 221 



Avith which I can compare it is Spiriferina stracliei/ i Salter from 

 the Himalayan Muschelkalk, which Eittner says is rather closely 

 related to the Em-opean Sp.fragiUs ; but the form here described 

 is ]nnch larger, and is more strongly ribbed. 



Spteiferixa gypaetus, sp. nov. (PI. XXIY, fig. 4.) 



Shell extremely alate, the wings towards their apices tapering 

 rapidly to sharp points. The ventral area is very long, concave, 

 and narrow, and is faintly striate. The beak of the ventral valve 

 is very small, and projects but slightly above the hinge-area ; it 

 practically touches that of the dorsal valv^e, which is broad and 

 projects slightly above the dorsal area. 



The dorsal valve has a broad, median, triangular, rapidh^-widen- 

 ing fold, with a fairly-deep angular sinus on each side of it. The 

 first lateral folds on each side are lower and rather narrower than 

 the median one, and on either side of these are three much smaller 

 and fainter lateral folds which gradualh" decrease in size. All the 

 folds continue to the beak. The wings towards the apices are free 

 from folds. The anterior outlin'e of the shell is gently rounded, 

 and narrows rapidlj'^ towards the wings, Avhich continue ver}'" narrow 

 for some distance, ending in sharp points. The growth-lines are 

 prominent, irregularly spaced, and rather foliaceous. 



Length =22 mm. ; width = 75 mm. 



Localit}^ and horizon. — A very fine cast of the ventral beak 

 and dorsal valve, from which I made a gutta-percha squeeze, comes 

 from the slopes of South Peak (Benmore), in the Hokonui Hills, 

 and belongs to the New Zealand Geological Survey. The horizon 

 is probably Noric. 



Spieieerixa acutissima, sp. nov. (PI. XXIY, fig. 3.) 



Shell extremely alate ; the wings are produced into very acute 

 points. The hinge-area extends the whole length of the wings, is 

 very narrow, concave, and faintly striate parallel to the margin. 

 The ventral beak is very small, and projects but slightly above the 

 hinge-area ; that of the dorsal valve is also small, and scarcely pro- 

 jects above the dorsal area, and the two almost touch one another. 



In the dorsal valve the median fold is high, narrow, and trian- 

 gular, and has a ver}*" faint m.edian sulcus on its anterior portion. 

 On each side of it are six similar folds gradualh^ decreasing in 

 size and height, the last being very faint. The folds continue 

 to the dorsal beak, and are divided by rather deep and angular sulci. 

 The anterior margin is very narrow in proportion to the width of 

 the shell, the lateral margins narrowing gradually to the wings, 

 which are considerablj^ produced and end in very fine points. The 

 growth-lines are not very prominent. 



Length = 21 mm. ; width = 83 mm. 



Locality and horizon. — The New Zealand Geological Survey 

 possesses a very fine mould of the ventral beak and dorsal valve in 

 hard dark greywacke, from which I took a gutta-percha squeeze. 



