16 



M.K. HOWARTH AND N.J. MORRIS 



JEBEL BILLUM 



Qishn Formation 



I I ; 



< 1^—— 



i4 



m 



Tj.- 



■ ' ' r"* 



I II') 



1~7T 



I I U 



nil 



I I ^ 



Madbi Formation 



1 2 Substeueroceras koeneni (Steuer) 

 1 Substeueroceras striatum sp. nov. 



Uhligites kraffti (Uhlig) 

 Virgatosphinctes cf. 6/-0///V (Uhlig) 

 Choicensisphinctes Hmitis (Burckhardt) 

 Substeueroceras koeneni (Steuer) 

 Substeueroceras striatum sp. nov. 

 Blanfordiceras walliclii (Gray) 



52 



- Corals 



Uhligites kraffti (Uhlig) 



lAspidoceras sp. Indet. 



Laevaptychus 



Spiticeras sp. indet. 



Virgatosphinctes cf. 6ao///7 (Uhlig) 



Choicensisphinctes limitis (Burckhardt) 



Berriasella (B.I oppeli (Kilian) 



Berriasella sp. indet. 



Substeueroceras koeneni (Steuer) 



Malbosiceras cf. aizyensis Mazenot 



Neocrassina spitiensis (Stoliczka; Holdhaus) 



5 Glochiceras (G.I subclausum (Oppel) 

 1 Orthosphinctes polygyratus (Reinecke) 



2 Paryphoceras grayi (Spath) 



4 Larcheria gredingensis (Wegele) 



1 9 Orthosphinctes polygyratus (Reinecke) 



1 Euaspidoceras sp. indet. 



Fig. 12 Vertical section of the Naifa and Hajar Formations in Jebel Billum; the upper half was obtained from the Eastern Jebel Billum locality (EJB on 

 Fig. 7), the lower half from the nearby Perisphinctid Cliff (PC on Fig. 7); the 5 Glochiceras and 1 Orthosphinctes 18-20 m above the base of the Billum 

 Member were collected in the western entrance road cutting to Jebel Billum. 



