24 CALCAREOUS ALGAE OF THE MIDDLE EAST 



Atractyliopsis darariensis sp. nov. 

 (PI. 2, figs. 3, 4, 5) 

 i960 A. lastensis Accordi ; Elliott : 219. 



Description. Hollow cylindrical tubular structures, straight or gently curved, of 

 up to 5-0 mm. observed length, 073 maximum external diameter : walls formed of a 

 single layer of adjacent, touching or fused hollow spheres of 0-13 mm. internal 

 diameter, original wall-thickness of spheres variable but 0-010-0-020 mm. in detached 

 spheres. Primary calcification variable : the spheres may be more or less set in 

 calcite formed by their fused walls, or almost isolated, with the outer surface of the 

 cylinder truncating their outer curves, sometimes completely, to leave external 

 openings, and their inner curves projecting roundly and unabraded into the cylinder- 

 cavity. 



Horizon. Upper Permian of Northern Iraq. 



Holotype. The specimen figured in PI. 2, fig. 5, from the Upper Permian Darari 

 or Upper Chia Zairi Formation, Ora, Mosul Liwa, North Iraq ; V. 52037. 



Paratypes. The specimens figured in PL 2, figs. 3, 4, same horizon and locality 

 as the holotype ; V. 52015, 52037. 



Other Material. Fragments in random thin-sections, same horizon and 

 locality. 



Remarks. This is very closely related to the type-species A. lastensis Accordi 

 from the Upper Permian Dolomites of Northern Italy (Accordi 1956). Both occur 

 with a similar Gytnnocodiuni-floTa. in a rather similar facies at the same level. A. 

 darariensis is described here as distinct since the cylindrical remains seem to have 

 been markedly longer than in the Italian species, but the two are probably con- 

 temporary geographical species at most. Much depends on secondary calcification, 

 which has to be distinguished very carefully where possible from that of the original 

 sporangial coatings, and the Italian and Iraqi specimens are differently preserved in 

 this respect. The measurements given above under " Description " are carefully 

 taken from specimens without secondary calcification, or with it easily distinguish- 

 able as such when present. In the Italian topotype material available to me 

 Atractyliopsis lastensis is much more abundant than in the Iraqi material, where A. 

 darariensis is a minority-constituent in a flora of Gymnocodium and Permocalculus. 



The Iraqi species is distinct from the Austrian A. carnica E. Fliigel. Although 

 described in great detail (E. Fliigel 1966), the abundant material figured and 

 described by this writer shows only circular and oval cross-sections. 



Praturlon (1963a : 132) has figured a thin section which shows Atractyliopsis set 

 vertically (axially) within Permocalculus cf . forcepinus (Johnson) , (Chaetangiaceae or 

 perhaps Codiaceae). He makes the interesting suggestion that this is the asexual 

 form of the species, which is associated with other specimens of Permocalculus show- 

 ing normal " sporangia " (Pcystocarps) and regarded as the sexual form. That is, 

 the Atractyliopsis is to be regarded as part of the internal structure of the Permo- 

 calculus, and is therefore not a dasyclad, nor indeed, a separate alga at all. 



