part 3] AMMONITES FROM NEW ZEALAND. 293 



auxiliary saddle unsymmetrically so, as in fig. 8 of G-emmellaro's 

 pi. ii. Apparently there is only one more auxiliary saddle, 

 whereas Rhacophyllites gigas Fucini, 1 Rh. transylvanicus 

 (Hauer) 3 and the varieties of that species in Fucini 3 which 

 agree with the New Zealand example in the small umbilicus, have 

 more numerous auxiliary elements. 



There are two or three (indistinct) constrictions and an irregu- 

 larity in the costation, due to an injury, which helps to accentuate 

 the ibes-Yike appearance of the specimen, reminiscent of the two 

 Tragophylloceras of the wechsleri group, figured by Wright, 4 or 

 •of Amphiceras mariani Gemmellaro. 5 



' Rhacoceras ' numismale (Quenstedt) Fucini, 6 which has a 

 flattened aspect, similar to that of the specimen here described, is 

 fairly involute, but badly preserved, and may only be a narrowly 

 umbilicated Rhacophyllites, not a Tragophylloceras. 



The example of Rhacophyllites cf. gigas Fucini, recorded by 

 Diener 7 from the Himalayas, represents a more evolute and less 

 coarsely costate form than the New Zealand specimen. 



An example of Rh. liberties (Gemmellaro), from the Upper Lias 

 of Foci di Cantiano in the Apennines (B.M. No. C8410), labelled 

 Ammonites (Rhacophyllites) diopsis Gemmellaro, by Prof. Zittel 

 himself, like the Sicilian type 8 or like another example from the 

 Valley of Kelat, Baluchistan (Geol. Soc. Coll.), is more evolute and 

 has less coarse costation than the New Zealand form. 



Localitv and horizon as above. 



Genus Thysanoceras Hyatt, emend. S. Buckman. 



Thysanoceras cf. cornucopia (Young & Bird). (PI. XVIII, 

 figs. Sa&Sb.) 



A fragment of a Lytoceratid, in whorl-shape and ornamentation, 

 olosely resembles Young & Bird's 9 Yorkshire species, to which a 



1 Op. cit. 1901, p. 56 & pi. ix, figs. 2, 4. 



2 In Herbich, ' Das Szeklerland ' Mitteil. Jahrb. K. Ungar. Geol. Anst. 

 vol. v (1878) p. 114 & pi. xx j, fig. 1. 



3 Op. cit. 1901, pp. 53, &c. & pi. viii, figs. 1-7. 



4 ' Monograph of the Lias Ammonites ' Pal. Soc. pt. iii (1880) pi. xxxix, 

 figs. 1-3 (JEgoceras loscombi Sowerby). These specimens are not in the 

 Wright Collection in the British Museum ; but fig. 3, to judge by a Eadstock 

 example, may be a badly drawn Tragophylloceras wechsleri, whereas figs. 1 & 2 

 represent a form with broader periphery sufficiently distinct to receive a new 

 name (T. radstockense nov.). 



5 ' Sui Fossili dei Strati a Terebratula aspasia ' pt. i, Soc. Sci. Nat. & Econ. 

 Palermo (1884) p. 33, & pi. i, figs. 13-14 (typus). 



6 Op. cit. (1901) p. 15 & pi. ii, fig. 4. 



7 ' Upper Triassic & Liassic Faunse of the Exot. Blocks of Malla Johar, 

 &c.' Mem. Geol. Surv. India, Pal. Indica, ser. 15, vol. i, pt. 1, p. 76 & pi. xi, 

 fig. 1. 



8 Op. cit. (1884) p. 4 & pi. ii, figs. 1-2. 



9 ' Geol. & Miner. Survey of the Yorkshire Coast ' 1822, pi. xii, fig. 6, as 

 interpreted in S. S. Buckman, ' On Lytoceratidse ' Q. J. G. S. vol. lxi (1905) 

 p. 149. 



