W. LEUCKAETI. — SPICULATION. 287 



with a greater number of rays, as, for instance, hexactins witli 

 one of the axes elongated considerably more than the others. 



The oxydiactin prmcipalia may measure 35 mm. in length 

 and 120/^ in breadth at the middle. They are usually nearly 

 straight and smooth throughout. They are present as usual in 

 all sizes, grading down to fine accessoria which occur either as 

 comitals or singly by themselves. Tlie accessoria are of only 

 7-11 fji breadth, either plain or annulated at the center, and sub- 

 terminally swollen and rough-surfaced, the extreme end being 

 rounded or obtusely pointed. 



At the juncture of a primary branch with the stem, the 

 axial parenchymal bundle of the former joins the outer bundles 

 of the latter. At the root of the branch some of the fibers pene- 

 trate for only a short distance into the said parietal bundles ; 

 others are seen to spread out in all directions among these. A 

 similar arrangement obtains at the origin of secondary and 

 tertiary branches. 



The coalescence of the parenchymalia by simple fusion as well 

 as by numerous synapticula? is carried on to a great extent in 

 the stem. Only for a short stretch at the apical end the paren- 

 chymalia are all loose. The ankylosis is especially dense nearer 

 the gastral surface and towards the basal end. It extends into 

 the base of the primär}^ branches and often farther outwards, but 

 seldom into the secondary branches. 



The greater part of the basal disc is composed of parenchymal 

 diactins disposed not in strands but rather in a feltwork-like 

 arrangement. They are compactly soldered together in a close- 

 meshed framework. The compactness increases from the superior 

 surface inwards. On the inferior surface, in direct contact with 



