E. MARSHALLI. — SPICULATION. 97 



annular swelling or by eruciately disposed knob-like rudiments 

 of the suppressed rays. The prolonged eomital rays are mostly 

 under 25 /t in breadth near the center; they taper outwards, 

 thence to maintain a nearly uniformly thick, filamentous caliber 

 to the end, which is rounded or conically pointed and subter- 

 minally rough-surfaced. 



Scattered here and there among the fibers of the beams in 

 question, I have on certain occasions found small hexactins, 

 pentactins, stauractins and such like, whose short rays made them 

 appear to be somewhat distinct from the other much elongated 

 elements but which are probably to be classed together with 

 these simply as cases of arrested development. 



The oblique beams of the skeleton show a similar composition 

 save the absence of stauractin-principalia. Slender thetactins and 

 paratetractius predominate among their elements ; frequently 

 intermixed with these are pentactins and hexactins of moderate 

 strength. Just the same elements constitute the parenchymalia 

 of the flake-tissue, in which they are arranged either loosely or 

 in snuill bundles. A number of the latter in radial and rafter- 

 like arrangement serve to support the parietal ledge, similarly 

 as described by F. E. Schulze ('87) iov^E. aspergillum. 



As a category of spicules closel}' associated with parenchy- 

 malia must be considered t\\& prostal oxydiactlns, which, occurring 

 in comitalia-like bundles around the distal rays of certain der- 

 malia, cause inconspicuous bri;tle-like projections along the edge 

 of the cuff and of certain parietal crests. The same sort of 

 spicules is also known in E. imperiah's, E. ^nodosa, &c. (p. 72). 

 In the present species, the oxydiactins in] question are small, 

 being at most about 1 ram. long and not exceeding Sn in thick- 



