20 ART. 9. — I. IJIMA : HEXACTINELLIDA. 



the lateral wall to an extent of about 55 mm. or less in length. 

 A short distance from the top, the diameter of the body must 

 have measured nearly 70 mm. The lateral wall slightly closes in 

 towards the sieve- plate margin, somewhat as in Regadrella phœnix 

 (Ij., 'oi, p. 267). The entire length of the original individual 

 can of course not be ascertained. That the base was firmly fixed 

 to a hard substratum may be concluded from the state of that 

 part in Specimen B. 



The sieve-plate closely resembles that of Eupleciella or of 

 Regadrella. The meshes are oval, ovoid, triangular or quad- 

 rangular with rounded corners, some of the largest measuring 

 :>j mm. across. The beams are laterally compressed and measure 

 up to 1 mm. or thereabout in breadth as seen from above. Many 

 of them are perceptible as more or less radially directed, especially 

 in the peripheral part of the sieve-plate. 



The ring-like edge of the sieve-plate is well marked. Here 

 all around was probably originally present a low continuous ridge, 

 which is at places still preserved with fine palisade-like marginalia 

 projecting out to a length of nearly 2 mm. 



The lateral wall, much lacerated on the outside, is rather 

 thin. Its general appearance is very much like that of the same 

 part in Eupleciella imperially or in E. marshalli, in a similarly 

 macerated state of preservation. Externally are seen a number 

 of parechymal bundles running for the greater part obliquely. 

 Beneath these is the more strongly developed system of longitudinal 

 bundles. As has been correctly noted by Bowerbank ('67, p. 

 358), these bundles for the mcst part terminate when they reach 

 the marginal ring ; the rest cross it and pass continuously into 

 the sieve-plate beams. Internal to all is the system of wavy 

 transverse bundles, which together with the longitudinal forms a 



