29G DP. L. F. SPATH ON [vol. lxxix, 



of the external saddle, however, the outer (siphonal) pair are at a 

 higher level than the inner pair, and the inner of the two leaflets of 

 the first lateral lobe is higher than the outer in the New Zealand 

 form, points in which there is agreement with PhyUoceras passati. 



Since the species now described is probably new, it is of no use 

 for dating the beds at Totara Point. The resemblance of the 

 ribbing to that of the Argovian Ph. passati ruay be of no signi- 

 ficance ; and, moreover, it is found again in the Callovian Ph. 

 mamapiricum Bcehm. 1 Bcehm considered it not impossible that 

 this species, as well as Ph. passati, may yet prove identical with 

 Ph. mediterraneum ; and it is noteworthy that the peripheral sinus 

 is more pronounced in the early t} r pes. On the other hand, the 

 mode of preservation of the specimens now discussed is exactly the 

 same as that of the PhyUoceras next described, from Kohai 

 Point. 



Locality. — Totara Point. With the smaller specimen, marked 

 ' Totara Point ' in ink, is, however, a label : ' Te Abu Ahu (by the 

 Old Mission Station) Belenmite-Beds.' A PhyUoceras from the 

 latter locality, belonging to Prof. Marshall, may belong to the 

 same species. 



Horizon.— Jurassic (Middle or Upper?). 



Phylloceeas cf. poltolcum (Benecke). 



1866. ' Trias & Jura in den Siid-Alpen ' Pal. Beitrage, vol. i, p. 182 & 

 pi. vii. 



An example of a PhyUoceras, measuring 180 mm. in diameter 

 and having an umbilicus of about 10 per cent., shows eleven angular 

 constrictions that pass straight across the peripheiw : that is, there 

 is no ventral sinus as in the form just described, with which, how- 

 ever, it agrees in mode of preservation. There is also no ribbing on 

 the periphery, but at a corresponding diameter PhyUoceras aff. 

 mediterraneum is equally unornamented. Like the latter, the form 

 now described clearly belongs to the group of PhyUoceras ultra- 

 montanum (Zittel), and differs from Beneeke's type merely in not 

 acquiring its eleven constrictions until a larger diameter. PhyUo- 

 ceras tauricum (Betowski) = Ph. mediterraneum, var. tauricum," 

 with only seven to eight constrictions at a smaller diameter, may 

 thus be as close to the New Zealand form as Beneeke's species ; 

 but Neumayr 3 had pointed out that his numerous examples of 

 Ph. polyolcum from the acanthicus zone had only nine constric- 

 tions up to a diameter of 100 mm., and seven to eight at a still 

 earlier stage. 



According to the same author, the suture-line of Ph. polyotcum 

 is slightly more slender than that of Ph. mediterraneum ; but in 



1 ' Unteres Callovien & Coronatenschichten, &c.' Nova Guinea : Result. 

 Exp. Sci. Neerl. 1903, vol. vi, Geol. i, Leiden (1912) p. 7 & pi. i, fig. 3, 

 id. ii, figs. 1-2, text-fig. 1. 



2 ' Die Tithoniscben Ablagerungen von Tbeodosia ' Bull. Soc. Imp. Nat. 

 Moscou (1893) nos. 2 & 3, p. 231 & pi. ix, fig. 5. 



* Jahrb. K.K. Geol. Reichsanst. vol. xxi (1871) pp. 341-42. 



