PAROPSONEMA CRYPTOPHYA 175 



braids of the median series are terminated and new series in- 

 itiated, these arising within the branches mentioned. Several 

 specimens show very clearly that the new series of braids begins 

 at a given radial length and forms a distinct cycle. Still another 

 bifurcation of the smooth radii occurs about half way between 

 the first cycle and the margin of the disk, and this again occurs 

 at the same radial distance for each radius. Each smooth in- 

 tercalary area which starts from the center is represented by 

 four branches at its distal termination. All radii, both struc- 

 tural and structureless, taper and become extinct within the 

 margin of the disk, leaving a smooth border about the disk. 

 The actual structure of the radial areas which we have spoken 

 of as braids, though not apparent about the center, becomes 

 clearer as these areas widen in the second cycle and pass to their 

 final extinction in the third. 



It is necessary to premise that the specimens showing this 

 surface of the disk are preserved as sculpture casts, so that, 

 while the actual substance of the body has been removed without 

 replacement, we see the surface with the original relief of the 

 exterior. 



The broader parts of the radial braids, from near the com- 

 mencement of the second cycle to their extinction, bear a regu- 

 lar succession of horizontal toyvs, of pores. Beginning at the 

 lateral margin of one of these poriferous areas or braids, two 

 adjoining rows of pores will be found to converge slightly and 

 terminate by such convergence. Such a pair of rows will have 

 the position of its apex on or near the central line of the area 

 and between the apexes of two similar pairs on the other half 

 of the area. The rows of pores are separated by low ridges on 

 the sculpture cast, but the ridges between rows of the same 

 pair are distinctly less prominent than those between adjoining 

 pairs. This structure is, as observed, most clearly retained over 

 the second cycle of braids, where their diameter is greatest and 

 both pores and poriferous plates are most pronounced; outward 

 toward the periphery the horizontal extent of the pore rows 

 is less, the pores themselves more restricted to the margins of 

 the area and apparently of considerably larger size. The effect 

 of this structure is to make the poriferous bands appear to 



