54 Bulletin Vanderhilt Marine Museum, Vol. VII 



length to the radius of the disk and extend almost to the circum- 

 feral margin when laid out flat. The upper simple axial shaft of 

 the proximal part of each arm is about two-fifths of the total 

 length, while the three-winged distal part is three-fifths of this 

 length, Y-shaped in cross-section and almost as wide as long. The 

 free margins of this Y are multiple-branched and folded and bear 

 the frilled mouths. Each lamella of the mouth-arm has seven or 

 eight deep clefts. There are many small club-shaped vesicles 

 scattered among the frilled mouths and several larger terminal 

 clubs along the lower or outer end of each arm. Numerous strong, 

 tapering filaments occur between the mouths along the side of the 

 arm. The rows of frilled mouths along the axial side of the arms 

 extend to the center and here form a rosette-like arrangement. 

 There are present a great many long, tapering, thread-like fila- 

 ments that arise independently and hang down. The central 

 stomach is cruciform, the arms being perradial. Four perradial 

 canals extend direct from the four angles of the central stomach 

 to the four perradial sense-organs respectively. From each of the 

 four interradial sides of the stomach there arises a network area 

 of anastomosing capillary-like vessels, from each area of which 

 arises an interradial canal that extends to the four perradial sense 

 organs. Some few branches from the anastomosing interradial 

 area extend out and unite with the perradial canals. All eight 

 radial canals are intercommunicant through another zone of anas- 

 tomosing vessels near the margin, some of which vessels extend 

 into the lappets, this marginal network fulfilling the function 

 usually performed by a true ring caiial, which} is absent in mem- 

 bers of this genu^. There is also a main canal arising from each 

 of the four perradial corners of the central stomach which goes 

 down into the arms, where it branches complexly, these branches 

 going into the mouth-arms. 



The umbrella is strengthened by a wide area of concentric ring 

 muscles, the outer portion of which extends close to the marginal 

 lappets ; the ring is divided into eight sectors by as many radial- 

 canals. On either side of each radial-canal and parallel thereto 

 are narrow areas of fine radial muscles, supporting the umbrella 

 and in a measure protecting the canals. 



References : Versura palmata, Haeckel, E., Syst. der Medusen, 

 1879, Bd. I, Densch. Med.-Naturwiss-Gessellsch. zu Jena, 



