Art. I. — On the Occurrence of the Anchoring Tubes of 

 Adeona in the Older Tertiaries of Victoria with 

 (in Account of their Structure. 



(Plate I.). 



By T. S. Hall. M.A., 



Demonstrator and Assistant Lecturer in Biology in the University 

 of Melbourne. 



[Bead 12th March, 1896.] 



In the residue obtained from washing samples of the older 

 Tertiary marine clays of various parts of Victoria, there occur 

 numerous small cylindrical calcareous bodies, the nature of which 

 has long been a puzzle to those who have examined them. 

 Recently, while examining some specimens of Adeona in the 

 collection of the late Dr. MacGillivray, in which the anchoring 

 tubes were well preserved, the resemblance of the joints of the 

 anchoring tubes of the jDolyzoon to the objects in question struck 

 me very forcibly, and a dried specimen in the collection of the 

 Biological School afforded sufficient material for making a careful 

 comparison with the fossil forms. 



The fossils are very variable in size and shape, but speaking 

 generally they are cylindrical objects ranging up to about 3 mm. 

 or 4 mm. in diameter and to about 5 mm. in length. The two 

 terminal plane faces of the cylinder are generally perpendicular 

 to its long axis, and are pierced by a number of fine pores, which 

 are apparent without the aid of a lens. The lateral wall of the 

 cylinder is formed by closely applied threadlike cords which 

 branch and anastomose, leaving narrow elongated pores between 

 them, the long axis of the pores coinciding in direction with that 

 of the cylinder. Usually the diameter of the cylinder slightly 

 increases somewhat suddenly at each end. In many cases the 

 joints are branched, three branches sometimes meeting at one 

 point. The pi'oportion of the length of the cylinder to its 

 diameter varies greatly in different specimens. Some are very 

 elongate, while others are flat discs, all grades between the two 

 extremes being found. <■ 



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