part 3] THE TEIAS OF Is'EW ZEALAjS^D. 197 



the middle of the hinge-marghi. There is no anterior ear as in 

 Hnlohia, and consequently there can be no doubt that this shell 

 belongs to the genus Daonella. The ribs coininence near tlie beak, 

 onlj a small arja of which is free from them, and sweep regularly 

 down to the margins. Secondary furrows commence some distance 

 from the beak, bat do not reach the depth of the primary furrows, 

 and it is only occasionally that a rib is divided by two furrows. 

 Concentric ripples are confined to the umbonal regions, and 

 growth-lines are scarcely seen. There is a very narrow triangular 

 space extending along the posterior hinge-margin, Avhich is free of 

 ribs. It attains a considerable size : a fragment of a large 

 specimen in my collection (PI. XX, fig. 7) shows that it must 

 have been about 70 mm. long and 60 mm, high. 



Locality and horizon. — In New Zealand th's form is con- 

 fined to the Kaihiku Beds, and affords verj^ strong evidence that 

 these are of Ladinic or Lo\ver Carnic age. It seems to occur in 

 all the localities where the Kaihiku Beds are found. I collected 

 :several specimens in the Caroline Cutting on the south side of the 

 Hokonui Hills, and on looking over the Geological Surve}" Collec- 

 t^ion I identified many specimens from the Nelson district, Mount 

 Potts, and other localities. 



Remarks. — This is the only member of the Daonella^ and 

 HaJohia group tliat occurs in the Kaihiku Beds, and seems to be 

 in every way identical with the Himalaj^an form. It belongs to 

 ths group of D. fj/rolensis of the classification of Mojsisovics, from 

 which it differs in details well defined by Bittner. It resembles 

 also in som3 ways IK snkawann Mojsisovics, a Japanese fossil. It 

 is widely clistribated in the Himalayan Trias, and in the Shal- 

 Shal section and other localities, occurs in a bed which Diener took 

 to be the top of the Muschelkalk complex, but later attributed to 

 the Aonoidns Beds. Wanner ^ records it, figuring specimens from 

 tlie southern coast of Timor, and regards it as marking the base 

 of the Uppei' Trias. This form has not been recorded from New 

 •Caledonia. In the Spiti district of the Himalayas-^ it is associated 

 with D. lommeli^ a well-known Alpine Ladinic fossil. 



Halobia zittelt Lindstrom, var. zealandica, nov. (PI. XX, 

 fig. 6, & PL XXI, figs. 1-2.) 



Beak rather prominent, somewhat inflated, directed forwards, and 

 isituated rather in front of the middle of the straight hinge-line. 

 The anterior ear is broad and well marked, triangular in outline ; 

 it widens out rapidl}^ and is strongly arched and rounded. This 

 ■ear is marked otf from the rest of the shell by a broad shallow sulcus. 

 The radial ribs begin just below the beak as a series of closely-set, 



"■ The fossils which Zittel identified asHnlobia ?o/H)neii were later described 

 by Mojsisovics as Halohia liochstetteri. H. lommeliis really a Dn one? fa. The 

 true D. lommeli, a Ladinic fossil, does not seem to occur in New Zealand, the 

 Kaihiku horizon being apparently too high for it. 



'- Bibliography, 49, p. 202. ^ Bibliography, 10, p. 11 & pp. 143-45. 



«Q. J. G. S. No. 291. R 



