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BULLETIN 65, UNITED STATES NATIONAL MUSEUM. 



especially around the bifurcations that the meshwork tends to depart from 

 regularity and the branches to become tlexuous. The dissepiments are all very 

 slender, and are very numerous. They are all transverse or only very slightly 

 oblique. Most of them are 1 mm. apart, though on a general average there 

 may probably be as few as 20 in 25 mm. The greatest distance between con- 

 secutive dissepiments seems about 1..5 mm. Occasionally two may be very 



close together (0.4 mm.). Of course, being so very slender and the branches 

 being comparativelv stout, it often happens that an apparently well-preserved 

 IH.lvparv mav show the branches well preserved though the dissepiments have 

 suffered. The meshes are rectangular, except where flexuosity of the branches 

 renders them irregular. The thec:e, or rather indications of them m the form 

 of oval elevations, are frequently well preserved, so frequently and so well 



