70 



Bulletin Vanderbilt Marine Museum, Vol. VII 



thickly encrusted by small pebbles, shells, sand and similar detri- 

 tus. The disk is also sand-encrusted, but in less degree. The disk 

 is mammiform in the dead shrunken polyp, with a diameter equal 

 to approximately one-third of the height of the polyp, and having 



Text figure 4. — Gemmaria marquesana Boone, type, cross-section 

 of a single polyp, greatly enlarged. 



a decidedly "ribbed" appearance, having about thirty elevated 

 radii alternating with as many radial grooves. The radii are 

 encrusted and have a rough surface. The tentacles are in two 

 series, about sixty-four in number, thirty-two per series. Each 

 tentacle is wide, shortish, blunt tapered, conical, about one-third 

 as long as the disk diameter in the dead specimen. The actinostome 

 is slit-shaped, the actinopharnyx brief, tubular, the enterostome 

 leading into the coelenteron, which contains about sixty mesen- 

 teries of two kinds, i. e., thirty primary mesenteries alternating 

 with thirty secondary mesenteries, which are smaller, being 

 scarcely half so wide as the adjacent primary mesenteries. Each 

 primary mesentery bears along the inner free edge the corkscrew- 

 like filaments, extending about half the length of the stomach 

 cavity below the enterostome. 



