382 Transactions. 



This species was distinguished by its author from A^. lenticularis for 

 much the same reason as in the case of N. camphellica — viz., the narrower 

 shell — but it may be distinguished from the latter by its broader and less 

 curved hinge -line, the sides making an obtuse angle with the beak. The 

 beak is less produced dorsally of the hinge-line and is erect, with a foramen 

 rather larger than that of N. campbellica and iV. lenticularis. 



As thus defined the species is common in the Wanganuian, and there 

 are several specimens from the uppermost Mount Brown limestone which 

 may be referred here. 



St 

 Neothyris novara Iher. - 



1864. Waldheimia lenticularis Suess, Reise der " Novara," Geol. 

 Th., bd. 1, abth. 2, p. 56, taf. x, figs. 3a, ia, 46 (not of 

 Deshayes). 

 1903. Magellania novara Iher., Ann. Mus. Nac. Buenos Aires, 



ser. 3a, t. 2, p. 326. 

 1905. Magellania novara Hutton, Trans. N.Z. Inst., vol. 37, p. 475, 



pi. xlv, fig. 3. 

 1907. Magellania Amegkinoi Iher., Ann. Mas. Nac. Buenos Aires, 

 ser. 3a, t. 7., p. 472 (not of Ihering, 1903). 

 As Ihering appears to have had before him at the^ time of naming this 

 only the description and figures of Suess, the specimens treated by Suess 

 must be regarded as the syn types. - Of these I select the specimen from 

 Motupipi (fig. 4a, 4&) as the lectotype. This agrees with Button's inter- 

 pretation of the species. Ihering in 1907 united the species with his 

 Magellania Ameghinoi, but since, the thickness of the latter is stated never 

 to exceed half the length, whereas in N. novara it is always more than half, 

 the two may be easily distinguished. 



The species is broadly oval like N. lenticularis, but has a much straighter 

 hinge-line. In the lectotype, and in a few specimens from the Weka Pass, 

 the sides make no angle with the beak; but in the majority of the specimens 

 from the Weka Pass, and also in others from the Takaka limestone, the 

 sides are less convex and make an obtuse angle with the beak. The 

 species is common in the uppermost Mount Brown limestone. 



Neothyris iheringi n. sp. (Plate XXV, figs. 1-3.) 



Shell broadly oval, beak fairly long, acute, hinge-line long and sharply 

 curved, sides convex, meetmg the beak and the rounded front without an 

 angle. Shell moderately convex, folding slight. Beak considerably pro- 

 duced dorsally of the hinge-line, erect and well detached from the hinge- 

 line, foramen small, mesothyrid, attrite. Length of holotype, 49-5 mm. ; 

 breadth, 44 mm.; thickness, 28-5 mm. 



This species differs from N. novara and agrees with N. lenticularis in 

 the strong curvature of the hinge-line. It is distinguished by the detach- 

 ment of the beak from the latter, in which the beak is incurved towards 

 the dorsal valve. 



Type locality : Uppermost Mount Brown limestone (E), Weka Pass. 

 The species is fairly abundant ia this locality, and is unknown elsewhere. 



Neothyris anceps n. sp. (Plate XXVII, figs. 7-9.) 



Shell ovate, beak large, obtuse, hinge-line rather narrow, strongly curved, 

 sides convex and rounded, greatest breadth anterior to the middle, front 



