564 me. l. f. spate: on [Dec. 1913, 



PHrLLOCERAS MANFEEDI (Oppel). 



1863. Ammonites manfredi Oppel, ' Ueber Jur. Amm.' Pal. Mitt. Mus. d. K. 



Bayeriscli. Staates, p. 215 & pi. lvii. fig. 2. 

 1871. JPJiylloceras manfredi Neumayr, ' Jurastudien : 3— Phylloceraten des 



Dogger & Malm ' Jahrb. K.K. Geol. Reichsanst. vol. xxi, p. 37 



& pi. xiv, fig. 8. 

 1907. Phylloceras of. manfredi Pervinquiere, ' Etudes de Paleontologie 



Tunisienne : I — Cephalopodes des Terrains Secondaires ' p. 13. 



A small ammonite, not very well preserved, seems to agree with 

 this form ; its dimensions are : — 



Diameter 23 millimetres. 



Height of the last whorl 55 per cent, of the diameter. 



Thickness of the last whorl 38 per cent, of the diameter. 



Umbilicus 9 per cent, of the diameter. 



These dimensions agree with those given by Neumayr. There 

 are also four constrictions which begin indistinctly near the um- 

 bilicus, and become wider and more conspicuous near the periphery. 

 The sides are bulging (as figured by Neumayr), and what can be 

 seen of the suture agrees also with fig. 8 & of that author. 



Pervinquiere records this form from Jebel Zaghuan, but thinks 

 that it is very difficult to determine whether his three small 

 ammonites belong really to the form here described or to Ph. puschi 

 (Oppel). My specimen shows neither the numerous constrictions, 

 nor the thin section and small umbilicus, of the latter form. 



The state of preservation of a second specimen, which I refer 

 doubtfully to Ph. manfredi (Oppel), is rather bad. 



Phtleoceeas cf. saxobticem Neum. 



1871. M. Neumayr, ' Phylloceraten des Dogger & Malm ' Jahvb. K.K. Geol. 



Reichsanst. voL xxi, p. 315 & pi. xiii, fig. 4, pi. xiv, figs. 1-2. 

 1907. L. Pervinquiere, ' Etudes de Paleontologie Tunisienne : I — Cephalopodes 



des Terrains Secondaires ' p. 12. 



A poorly-preserved cast, referred doubtfully to this form, has the 

 following dimensions : — 



Diameter 90 millimetres. 



Height of the last whorl 60 per cent, of the diameter. 



Thickness of the last whorl 32 per cent, of the diameter. 



Umbilicus 3 per cent, of the diameter. 



Neumayr' s form agrees so far very well, and in section especially ; 

 but on my specimen no trace of the umbilical rosette of virguloid 

 grooves is to be seen. Pervinquiere also mentions a rather 

 badly-worn specimen from the Lower Tithonian of Jebel Ben 

 Saidan, and this approaches to Ph. saeconicum Neum. in thickness, 

 but has no rosette. What there is to be seen of the suture-line, 

 especially the diphylloid external saddle and the triphylloid first 

 lateral saddle, seems to agree equally well with Neumayr's type. 



Since my specimen shows no trace of the original shell-ornament, 

 no comparison can be made with Ph. dyscritum Canavari — a form 

 distinguished from Ph. saeconicum Neumayr by prorsiradriate 

 lineation, instead of recti- to rursicostation. 



