7 o CALCAREOUS ALGAE OF THE MIDDLE EAST 



interpretations of various minor points and comparisons : it is, however, believed 

 that the summary above includes the essential differences. 



I described Pseudovermiporella as a problematicum, probably algal, and believe 

 that the presence of the inner thin-walled tube is important. It is not recorded in 

 Permian Vermiporella spp. elsewhere, and although it is not seen in all specimens, its 

 occasional presence unbroken and set in clear calcite free of the outer structures 

 suggests that it was part of the organism and not a later inhabitant of the abandoned 

 tube. It is, however, readily admitted that the exact nature of Pseudovermiporella 

 remains unknown : its description is included here as a doubtful dasyclad of the 

 Middle East. Giivenc (1965), who figures un-named species or forms from the 

 Taurus, leaves it as a problematicum. The microproblematicum Papillomembrana 

 from the Norwegian Precambrian (Spjeldnaes 1963) bears certain resemblances, from 

 the type-description. 



Note. The interesting study by K. B. Korde (Pal. Zhurn., 1966 no. 4) was seen 

 too late for proper discussion here, but briefly this authoress agrees with the probable 

 algal nature of Pseudovermiporella, whilst unable to place it taxonomically within 

 the algae. 



Pseudovermiporella sodalica Elliott 

 (PL 19) 



1958b Pseudovermiporella sodalica Elliott : 419, pis. i, 2, 3. 



i960 Pseudovermiporella sodalica Elliott ; Elliott : 219. 



1961 Pseudovermiporella sodalica Elliott ; Erk & Bilgutay ; 108, pi. 1. 



Description. Tubes of finely crystalline calcite, appearing white by reflected 

 light and dark in thin section, occurring commonly with various diameters up to 

 i-o mm. and sometimes attaining a diameter of 1-4 mm. The tubes are meandriform 

 and form tangled growths several millimeters across, in which apparently more than 

 one individual may occur. When a tube is free the cross section is circular, and 

 remains approximately so in many coils or loops, which touch in a growth or tangle. 

 However, when attached to others or to shell fragments, individuals occur which 

 show in thin section as arcs applied closely to the object encrusted, whose outer 

 surface completes the tube. 



The tubes are pierced by numerous closely set radial pores, approximately at right 

 angles to the axis of the tube, separated by interpore wall material which widens 

 slightly outward, or terminally, as seen in transverse and vertical sections. In adult 

 individuals the pores are about 0-030-0-040 mm. in diameter, circular in cross section, 

 about fifty to a transverse section of the tube, and the interpores of wall material 

 sometimes show a paired appearance in both transverse and vertical section. In 

 tangential sections the coarsely-pored wall shows as a regular and distinctive round- 

 pored mesh, with pores wider than interpores ; a count along a 1 mm. length of such 

 a section gave twenty-one regularly spaced pores. Such measurements are approxi- 

 mate only, due to the coiled tubes, which are at best only sinuous and never straight. 

 Smaller tubes show smaller pores. 



