Plate XVIII. 



Rhahdocalyptm victor It. P. 238. 



Fig. '2. A jiortion of tlie dermal surface, magnified about two diameters. 



Dermal lacework, blurred. Hypodermal strands radiating from 



several central points. 

 Fig. 3. A portion of the gastral surface, magnified about two diameters. 



Gastral lacework supported on hypogastral strands, covering the 



excurrent canalar apertures. 

 Fig. 4. A large, unequally rayed, parenchymal diactin from the l)asal 



region. 1.^0 x . 

 Fig. .3. A heraihexactinose oxyhexaster with nine terminal points. 300 x . 

 Fig. G, Portion of a discoctaster, with a primary terminal which has 



remained free, unfused wilh the secondary princip;il running by 



its side. 300 x . 

 Fig. 7. A hexactinose oxyhexaster. 300 x . 

 Figs. 8-11. Different forms of dermalia, the stauractinic form of fig. 10 



being by far the most common. 300 x . 

 Fig. 12. A discoctaster, with ]ilain central node. 300 x . 

 Fig. 13. A gastral hexactin. 300 x . 



Fig. 14. A small })ortion of the basidictyonal plate. 1,">0 x . 

 Fig. If). A hemihexactinose oxyhexaster with sev'en terminal ))oints. 300 x . 

 Fig. 16. A small portion of the ectosome, seen from outside ; including a 



group of hypodermal pentactins with the paratangentials in a 



radial disposition. In the center of the gronp, a dense projecting 



tuft of fine diactins, 30 x . 



