74 CALCAREOUS ALGAE OF THE MIDDLE EAST 



principal difference in thin-section is that whilst the stem-cell diameters are slightly 

 less in 5. apenninica, the external diameters are much less, so that the percentage 

 relation of internal to external is greater (50-60% against 33-40%). In 5. annulata 

 the distance between the external pores of the same verticil is said to be about equal 

 to the distance between two successive verticils (Carozzi 1955a) ; in S. apenninica the 

 former is less than the latter. The two species are very similar and obviously 

 closely related : in examining a series of either one finds atypical specimens showing 

 measurements more usual in the other species. In Italy they occur together over 

 the same range : in the Middle East they are apparently separate, S. annulata in the 

 south at Qatar and elsewhere, and 5. apenninica in the north in Iraq. Both these 

 occurrences are often in a similar oolitic facies, with associated fossils in common 

 (Clypeina jurassica, Favreina salevensis, Cladocoropsis, etc.). 



Salpingoporella arabica sp. nov. 



(PI. 21, figS. I-3) 



1955b Salpingoporella cf. miihlbergii (Lorenz) ; Elliott : 126. 



i960 Salpingoporella muhlbergi (Lorenz) , and 5 . muhlbergi var ; Elliott: 222-224. 



Description. Thin-walled tubular calcified dasyclad, straight-sided with very 

 gentle increase in diameter ; observed lengths (incomplete) up to 273 mm., external 

 diameter 0-31-073 mm., internal diameter 0-21-0-47 mm. ; ratio of internal to 

 external diameters 55-66% ; horizontal verticils set regularly 0-104 mm - apart, each 

 verticil with 8-10 branches which open rapidly and widely to external pore- 

 depressions of 0-065-0-078 mm. or more diameter. The wall calcification is thin and 

 rather ragged : the pores have a somewhat irregular appearance, partly due to the 

 wall-structure and partly due to slight irregular deviations from the horizontal in 

 their orientation. 



Horizon. Lower Cretaceous of the Middle East. 



Holotype. The specimen figured in PI. 21, fig. 3, from the Qamchuqa Formation 

 (Aptian-Albian level) of Surdash, Sulemania Liwa, Iraq. V. 52102. 



Paratypes. The specimens figured in PL 21, figs. 1, 2, from the top Qamchuqa 

 Formation (Albian level) of Sarmord, Sulemania Liwa, Iraq, and from the Upper 

 Musandam Formation (Lower Cretaceous) of Jebel Hagab, Peninsular Oman, 

 Arabia. V. 52100, 52101. 



Other Material. In Iraq, Qamchuqa Formation of Zibar-Isumeran, Mosul 

 Liwa (Barremian-Aptian level) ; Sarmord Formation of Jebel Gara, Mosul Liwa 

 (Valanginian-Hauterivian) and of Sarmord, Sulemania Liwa (Barremian). In 

 Arabia, from Haushi, South Oman, Lower Cretaceous probably Valanginian-Hauteri- 

 vian ; also from subsurface Upper Thamama Formation, ? Barremian-Aptian level, 

 of Murban no. 2 well, Abu Dhabi, Trucial Oman. 



Remarks. S. arabica is the Middle East form of the European S. miihlbergii 

 (Lorenz) Pia, with which I earlier tentatively identified it. The European species 

 from the Barremian-Aptian of France and Switzerland and the Lower Cretaceous of 



