562 mr. l. f. spath on [Dec. 1913, 



gently-bent constrictions, slightly rursiradiate near the periphery, 

 and its trifid lateral lobe. 



"With the material at rny disposal : that is, imperfect casts bearing 

 no trace of the shell-ornament, and showing only the suture-line 

 in disconnected portions, it is impossible to decide whether the 

 form should really be included in Xeumayr's Ph. mediterraneum ; 

 but the smaller number of constrictions (wmich seems very constant) 

 may well enable us to separate the Argovian forms from the type. 



ISTeumayr's form x came from the macrocephalus zone, and closely 

 comparable ammonites from the same beds have been figured by 

 Gremmellaro, 2 Popovici-Hatzeg, 3 and others. Dr. P. Lemoine * 

 has recently created the var. indica for the Indian form of Ph. 

 mediterraneum Neum. figured by Waagen, which occurs also in 

 Madagascar, being distinguished by less inclusion and a wider 

 umbilicus. All these Callovian forms have seven (or eight) 

 constrictions. 



Dr. M. Canavari describes the form from the Aspidoceras- 

 acanihicum beds. As he figures only a fragment, it is impossible 

 to say whether there is agreement with the Callovian forms ; but 

 the Argovian forms, at any rate, seem already distinct, and we 

 may reasonably doubt whether the ammonite really persisted from 

 the macrocephalus zone to the uppermost Jurassic, as is generally 

 assumed. 



Phylloceras zir/nodianum (d'Orb.), a form which differs only in 

 having more angular constrictions and a bifid lateral saddle, does 

 not seem to occur in Mediterranean deposits. 



An eighth specimen in my collection from Zaghuanhas straighter 

 constrictions and a smaller umbilicus than the other seven ; but 

 as the specimen is worn, and as one of A. de Biaz's figures 7 also 

 shows constrictions which on the cast are almost straight, I 

 include it here. 



Phtlloceeas cf. sttbptychoicum Dacque. (PI. LIII, fig. 1.) 



1873. W. Waagen, ' Jurassic Fauna of Kutch ' Pal. Indica, ser. 9, vol. i, 



p. 30 (pars) [as Ph. ptychoicum~\ & pi. vii, fig. 2. 

 1910. E. Dacque, ' Dogger &■ Malm aus Ostafrika ' Beitr. Palaont. Geol. 



(EsteiT.-Ung. vol. xxiii, p. 7 & pi. ii, fig. 1. 



One specimen in the collection belongs to the ptychoicum group, 

 but no labial ridges are visible. These, most probably, have been 

 worn down ; but, since they are absent on the chambered parts 



1 'Jurastud. 3: Phylloceraten des Dogger & Malm,' Jahrb. K.K. Geol. 

 Beichsanst. vol. xxi (1871) p. 340 & pi. xvii, figs. 2-5. 



2 ' Faune Giur. & Liass. della Sicilia' 1872-82, pi. xvii, fig. 2. 



3 'Cephal. Jurass. moyen du Mt. Strunga' Mem. Soc. Geol. France (Paleout.) 

 vol. xiii (1905) No. 35, pi. iii, figs. 9 & 10. 



4 ' Pal. Madagascar : pt. 8 — Amm. d'Analalava' Ann. Paleont. vol. v (1910; 

 p. 3 & pi. i, fig. 1. 



5 Pal. Indica, ser. 9. vol. i (1873) p. 34 & pi. v, fig. 1, pi. vii, fig. 3. 



6 'Fauna degli Strati con Aspidoceras acanthicum del Mte. Serra' Pal. Ital. 

 vol. ii (1896) p. 38. 



7 'Description des Ammonites des Couches a Peltoceras transversarium de 

 Trept (Isere) ' 1898, pi. xvi, fig. 10. 



