126 RECORDS OF THE AUSTRALIAN MUSEUM. 



tubes existed in the hard parts of Sponges, Foraminifera, Corals, 

 Brachiopoda, and Univalve and Bivalve Shells, and contained 

 sporangia ; he regarded them as unicellular fungi. The late Prof. 

 H. N. Moseley appears also to have worked at similar endo- 

 phytes in 1875, but I regret a want of knowledge of his 

 reference. 



The last paper to which I shall refer is Duncan's second com- 

 munication — "On bodies penetrating Recent and Tertiary Corals," 

 wherein he terms the form Achlya penetrans* He remarks that 

 a parasite closely resembling this lived in the tissues of tipper 

 Silurian Corals and Foraminifera, ''the main differences between 

 the ancient and modern forms consist in the larger calibre of some 

 of the filaments of the first, their long, often unbranching course, 

 and the frequent development of Conidia-\ook\ug bodies within 

 them, and the spherical shape of the spores." It does not appear 

 to be quite clear whether Duncan here retains the name he else- 

 where proposed for the " ancient " form, viz., Palceachyla j)erforans, 

 or includes both the "ancient and modern forms" under Achlya 

 penetrans. 



I am quite in accord with an observation of Mr. A. C. Seward,! 

 who says : — " It is generally a very difficult, and often an impossible 

 task, to discriminate between the borings of fungi and alg;e in 

 fossil material." In this belief I shall simply leave the tubes 

 described by me as Palceachlya tortuosa in the position formerly 

 assigned to them, pending furtlier investigations that future dis- 

 coveries may afford. 



The very much more intricate growth of the tubes described in 

 preceding pages, and their smaller calibre, induce me to consider 

 them as distinct from P. tortuosa of the PermoCarboniferous, and 

 for the sake of clearness they may be known as P. torqnis* 



In considering the systematic position of the moniliform chains 

 of cells, many difficulties present themselves, and in a preliminary 

 investigation of this kind — and it can only be considered prelim- 

 inary— I merely wish to point out the very strong general re- 

 semblance these chains of cells bear to certain unicellular algas of 

 the group Scliizophycere, and particularly the Nostocaceiie. The 

 moniliform chains are very like the trichomes of Nostoc, allowing 

 for the absence in the former of irregular interlacing, and the en- 

 larged black cells equally resemble the heterocysts of the same 

 genus, which seem to be — so far as my sections enable me to 

 judge — either basal, terminal, or intercalary. Compare the many 

 excellent figures given by Mr. M. C. Cooke, particularly those of 



* Proc. Roy. Soc, xxv , 1876, 174, p. 252. 

 t Seward— Fossil Plants, i., 1898, p. 129. 

 X i.e.. That which is twisted. 



