F()I:AMIXIFF.I!A ]IKr;0\-ALl.EX AM) EAULAND. 205 



walled, very linely striate, with line.s running radially Irom the apex to the periphery. 

 Marginal edge acute, with a tendency at Stations 5 and 6 to become carinate. Base, 

 flat with a small central umhilicus studded with beads. About four convolutions 

 (if long curving chambers, six to eight in the hist convolution. Viewed as an opaque 

 olijcct the dome-shaped glassy shell has a white spiral running round it from 

 apex to base, which, under higher magnilication, becomes resolved iiitu a line 

 of tubules extending through the thick wall of the chambers. 



Dimensions: — Width. -32- -37 mm.: height. -15 mm. 



This is one of the most distinctive N.Z. species, and is frecjuent at several 

 Stations, especially Stations 5 and 6. Budding (" plastogamic '"), and a few fossil 

 individuals at Stations 5 and 6. It appears to be most nearly allied to D. jnleoliis, 

 but has many distinctive characteristics. 



540. Discorbina tabernacularis, Brady. 



Disrorbiiia tnbeninciihiris, Brady, 1879, etc., RRC. 1881, p. 65; 1884, FC. p. 618, pi. Ixxxix, 



•figs". 5-7. 

 Heron-AUon and Earland, 19U. etc., FKA. l'.)15. p. 701. 



Stations 2, 3, 6. 

 All fossils. 



541. Discorbina cJisjmrilis, sp. nov. PI. YII. figs. 20-22. 



Station 2. 



Test compressed, consisting of aliout two convolutions, eight chaml^ers in the final 

 convolution rapidly increasing in size. Surface coarsely tul)erculate. Sutures 

 strongly limbate on the superior side, the sutures and the tuberculation rendering 

 the septation very indistinct. Marginal edge produced into a thick rounded 

 carina. Inferior surface slightly concave, smooth. Sutural lines very indistinct. 



Dimensions: — Length, • 38- -42 mm. ; maximum breadth, •30 mm. 



The above description is the best possible for a very obscure form repre- 

 sented l)y two specimens at Station 2. It is difficult to diagnose, owing to the 

 obscuration of all the earlier structure by the tuberculation of the superior sur- 

 face, and by the fact that the inferior surface, which is plane, is thick-walled 

 and opaque. The number and shape of the internal chambers can, however, 

 l)e made out by wetting the inferior surface. Its affinities are rather obscure; 

 it may belong to the D. biconcava group, but its nearest ally is clearly D. involuta, 

 Sidebottom (S.. 1918. FECA. p. 255. pi. vi. 15-17). which it closely resembles 

 in its superior and inferior aspects, but from which it differs in the absence of 

 the subsidiary septa which in Sidebottom's specimens suf)divide the internal 

 cavity of each chambei'. These, however, may be merely structural develop- 

 ments due to the deeper water from which his specimens were obtained. 



