RHABDOCALYPTÜS VICTOR. 251 



one specimeu. In other specimens I have sought after them in 

 vain, though certainly I can not be quite sure that they ^Yere 

 really totally absent in all these cases. 



As to the hasidiclyonal plate of the species (PI. XVIII., fig. 

 14), I have always found the structure to be thin and extremely 

 uneven. The irregularly contoured beams are sparsely micro- 

 tubercled. The meshes are small and roundish, oval or irregular 

 in shape. 



Soft Parts. 



A specimen of the size of an apple, killed and preserved in 

 alcoliol, was utilized for the study of the soft parts. However, 

 this led to no important results. Kot a little information as to 

 the arrangement of the soft parts may be gathered from figs. 18- 

 23 in PI. XIX. and from the explanations appended thereto ; 

 and I here limit myself to recording some of the points determined, 

 which are as follows : 



Chambers, 120,« in average diameter. j\Ieshes in their walls 

 open, generally 3-G /^ wide. Xuclei, about 2 /-« large in diameter ; 

 rather distinct though stained in about the same degree as the 

 reticulum-forming protoplasm ; containing one or more darkly 

 stained granules. At the chamber-rim (fig. 19), as also along the 

 termination of the chamber-layer close to the oscular edge (fig. 

 18), the finely reticular wall passes into film-like or filamentous 

 trabeculfe without any sharp demarcation. In the thin oscular 

 margin the chamber-layer assumes the character of a continuous, 

 irregularly undulating, reticular membrane, instead of being dif- 

 ferentiated into separate chambers (fig. 18). 



