186 



DlCTYOSPONGID^. 



obscuration of the latter. There is ranch variation in the size of these rods, 

 large and small ones being bundled together. In figure 37 is shown the 

 tenninal portion of one such rod. A close examination seems to establish 

 the fact that the majority of these lateralia terminate before reaching the 

 basal expansion and those which continue to the base of the cup are mainly 

 the rods of larsrest diameter. The horizontal bundles are of similar size, 

 but individual rods are frequently as large as any occuriing in the A'ertical 



Figure 37. Spicules of Cleodictya Mohri, T400, 1 , Terminal portion of vertical rod ; 8, umbel ; 8, the same from 

 beneath ; 4, mlcrumbel ; 5, C, the two sides of an entire trlplnulus ; 7, 9, 10, 11, 13, rarloufl fragments of plnulus 

 forms ; 8, Incomplete amphiaster ; 12, echinate hexact , H, 15, tpieuUn innominatcE ; 16, anchorate clavule , 

 17, rhabd showing concentric layers. (J. M. C.) 



series. Tlie ultimate quadrules, which measure about .5 mm., have at each 

 angle regular hexactins whose arms traverse more than one-half the length of 

 the contiguous squares, the extremital portions of adjacent spicules overlap, 

 ping. The outer vertical arm is sometimes modified into a blunt node. Such 

 hexactins are shown in figures 34, 35 and 36. There are also other regular 

 hexactins of large and small size with echinate arms, as shown by the frag- 



