CALCAREOUS ALGAE OF THE MIDDLE EAST 35 



terminal external diameter and 0-23 mm. internal diameter. This material is 

 insufficient for description, and it is not known if it corresponds with any of the 

 undescribed Cenomanian species listed by Emberger (1957). The remains were 

 associated with fine debris of codiacid algae. 



A third Cretaceous Clypeina occurred higher, in the Maestrichtian (Shiranish 

 Formation) of Diyana, Rowanduz Liwa, Iraq. It showed only a transverse section 

 of sporangial tubules of about 0-13 mm. diameter. This is quite inadequate for 

 comparison with such species as Clypeina sahnii Varma (1952) from the Danian of 

 India. 



Clypeina merienda Elliott 

 (PI. 4, figs. 2, 3, 7. 8) 



JO^b Clypeina merienda Elliott : 127, pi. 1, figs. 8, 9. 



Description. Fertile verticils disc-like, circular and flat, with diameter up to 

 2-5 mm., and diameter of central cavity up to i-o mm. The verticils consist of about 

 50 or more radiating hollow tubules, set nearly horizontally to the vertical axis, with 

 the tubules united laterally and often slightly expanded at the periphery, where they 

 are often open. Circular in cross-section, they have a transverse diameter of 0-15- 

 0-18 mm. measured in the mid-zone of large examples, with internal diameter of 

 0-072 mm., but examples with smaller diameters than this are common and there 

 would seem to be some variation in this character. The expanded and open tubule- 

 ends at the periphery are variable, and may be an indication of spore-shedding in 

 mature whorls. Internally each tubule communicates by a pore with the central 

 cavity : fused calcification forms a thickening in this central zone and extends down 

 to the next whorl. Up to six whorls have been seen in serial association as in life : 

 these whorls, measured vertically in the mid-zone of the tubules, from centre to 

 centre of consecutive whorls, were from 0-34-0-52 mm. apart. 



Horizon. Palaeocene-Lower Eocene of the Middle East. 



Material. In northern Iraq, from the Sinjar Formation of Banik (Mosul Liwa), 

 of Koi Sanjak (Erbil Liwa), and of Sirwan (Sulemania Liwa) ; also from the Kolosh 

 Formation of Surdash (Sulemania Liwa). In southern Iraq, the species occurs in a 

 fragmentary state in the Basita Beds of the Umm er Rudhama Formation (Palaeo- 

 cene-Lr. Eocene) near Aidah, Diwaniyah Liwa. 



Remarks. This Clypeina is distinctive in the large number of radial tubules per 

 whorl, in which character it somewhat resembles the larger Orioporella from the 

 Belgian Montian and Indian Danian (Morellet 1922, Pia 1936b), but with no trace of 

 the pores which perforate upper and lower surfaces of the tubules in this genus. 

 C. merienda is larger than the Eocene Clypeina spp. described by the Morellets 

 (1913 ; 1922) : the frequent flatness of its whorls is noticeable, though there is some 

 variation in this character. Of Middle Eastern species, it is the one in which serially 

 associated whorls, as in life, are most often seen in the fossils. 



