part 3] THE TEiAS OF :ffEW zeala:m). 183 



umbilicus. The living chamber is wanting ; but on the last whorl 

 two slightl}^- sinuous channels cross the venter and sides nearly 

 opposite one another, and represent former contractions of the 

 aperture. 



This specimen agrees in outer shape with Arcesfes r]i(Eficus, 

 a form for which Hyatt has proposed the new generic name- 

 RlicetLtes, but seems to differ in the sutures. Five saddles are seen 

 between the siphuncular saddle and the umbilical shoulders, the 

 fourth being higher up though not larger than the rest. The saddles 

 are deeply cut on each side into four auxiliary saddles, and the 

 siphonal lobe is divided by a saddle into two points which are not 

 deeper than the lateral lobes. In Arcesfes rhceticiis the sutures- 

 are said to form a series of lobes and saddles which gradually 

 decrease in size from the siphuncle, and the two siphuncular lobes- 

 are deeper than the lateral lobes. 



Mojsisovics says that Pompeckj considered Arcesfes rliceficiis 

 to be merely part of the inner whorl of an Arcesfes of the Graleati 

 group. 



Locality and horizon. — The specimen illustrated in PL XYII 

 was collected by Prof. Marshall and myself high up in the Phsetic 

 between Kawhia Harbour and Albatross Point, 3000 feet or more 

 above the Noric Pseudomonofis Beds. It is probabl}'" the highest 

 Triassic fossil that we obtained in New Zealand : it is entirely 

 distinct from the Arcestids in the Carnic, which are much smaller, 

 more involute, and lack the deep funnel-shaped umbilicus. 



Cladiscites sp. (PI. XYII, fig. 2.) 



Sides flat, sloping gentl}^ towards the small shallow umbilicus ,-. 

 venter gently rounded. The living chamber is missing and the 

 shell destroyed, and consequently it is impossible to see whether 

 there was any surface decoration. No specific name can, therefore, 

 be given. 



Locality and horizon. — The only specimen of this genus- 

 known to me comes from the JSfaufilus Bed at Mount Heslington, 

 Nelson. Carnic. 



PiXACOCEKAS sp. 



All the specimens of Pinacoceras that I saw are fragments of 

 air-chambers, and no satisfactorilj^-preserved example has come to 

 light. One cannot, therefore, say more than that this genus, or 

 some similar large and flat phylogerontic form with very compli- 

 cated sutures, occurs in the higher Triassic deposits. 



Locality and horizon. — I found a fragment in a bed at 

 Otamita, in the Hokonui Hills, which is probably Lower Noric ; 

 and in the Greological Surve}^ Collection is a piece of a very large 

 flat Pinacoceras, but with greatly eroded sutures, from beds on 

 the eastern side of Mount Heslington, near Nelson, which may also 

 be Lower Noric. 



q2 



