290 DE. L. F. SPATH OK [vol. lxxix, 



anisopliylluni), but there are important differences between the 

 New Zealand example and typical specimens of Wamner's two 

 species from the Schreinbach in the British Museum (Nos. 23116, 

 117, 118). The species to which the New Zealand form is now 

 attached shows, perhaps, more compressed whorls. It is probably 

 transitional to the forms mentioned above that lead to Discamphi- 

 ■ceras : that is, it is not of the W celineroceras stock. 



The Annamese Psiloceras longipontinum, above mentioned, 

 with an umbilicus of about 50 per cent, of the diameter, is more 

 evolute, and has longer ribs. Oppel's original 1 re-examined by 

 Neumayr, apart from being still more evolute, was described as 

 having, for a Psilonotus, narrow and sharp costse. 



Of Alpine forms of Psiloceras from the typical locality Pfons- 

 joch in the Tyrol, preserved in the British Museum, a specimen 

 close to Psiloeeras gemense Neumayr sp. (No. C 13864), with a 

 typically phylloid suture-line, is perhaps comparable with the 

 example here described ; but the latter, on the outer whorl, develops 

 the peculiar PJuphyllites -like costation of the other specimens 

 here described. 



Locality and horizon as above. 



(B) Middle Lias. 



Genus Phylloceeas Suess. 



Phylloceeas aff. paetschi (Stur MS.) Hauer sp. (PI. XVIII, 

 figs, la & 15.) 



Besides the figured example, of dimensions : 130, 56, 27, 11, 

 there is, in the British Museum, another worn specimen, consisting 

 of about half of an ammonite of similar size and showing the same 

 peculiar ribbing, distinguished from that of the Argentine form 

 figured by Burckhardt 3 by being continuous almost to the um- 

 bilicus. Similarly ribbed forms of Pliylloceras occur, of course, 

 at many horizons up to the Cretaceous ; but there appears to be 

 no figured example that agrees with the New Zealand specimens. 

 The reference to the Liassic partschi group is suggested by their 

 association with the Lytoceras and Rliacophyllites here described. 



Hauer's 3 type-figures are characterized by very straight costa- 

 tion, but other authors, as, for example, Greyer, 4 included in this 

 species forms with more sigmoidal and also more continuous costa- 

 tion, and Meneghini 5 drew attention to the variations in ornamen- 

 tation that occur in this group. The form figured by Beynes 6 



1 Pal. Mitteil. 1862, p. 129 & pi. xli, fig. 1. 



2 ' Beitrage zur Kenntnis der Jura- & Kreideformation der Cordillere ' 

 Palseontographica, vol. 1 (1903) p. 6 & pi. i, fig. 1. 



3 ' Beitrage zur Kenntnis der Heterophyllen der (Esterreichischen Alpen ' 

 Sitz. Ber. K. Akad. Wissensch. Wien, vol. xii (1854) p. 881 & pi. iv, figs. 1-8. 



4 ' Mittelliasische Cephalopoden des Schafberges, &c.' Abhandl, K.K. Geol. 

 Reichsanst. vol. xv (1893) p. 42 & pi. v : for instance, fig. 8. 



3 ' Fossil, d. Medolo ' in Stoppani : ' Pal. Lombarde ' Append. (1881) p. 27. 

 6 ' Monographie des Ammonites ' 1879, Atlas, pi. xxxiv, figs. 30-32. 



