286 BULLETIN OF THE 



PLATE IL 



Fig. 1. Cassiopca frondosa (aboral view). 

 " 2. The same (oral view). 



" 3. Linerges Mercurius (side view). The marginal lobes are infolded. 

 " 4. The same. The marginal lobes are extended and the crescentic form of 



the ovaries is shown. 

 " 5. L. Mercurius (aboral view). 



PLATE IIL 



Fig. 1. Portion of the oral surface of C. frondosa. 



" 2. Peripheral extremity of a canal lying in the central cavity between 

 two ovaries. Showing also the opening (b) leading from it into the 

 cliymiferous system of the oral arms. 



" 3. Oral cylinder cut off from the bell, so as to expose its cavity. 



" 4, 5. Life-size figures of L. ilercurius in attitudes assumed while swimming. 



" 6. Section cut through the cavity which lies above the stomach of X. Mer- 

 curius. One half this sinus is drawn in longitudinal plane, i. e. 

 section cut in the direction of the axis of the medusa. 



" 7. View of the opening by which this cavity communicates with the 

 stomach. 



" 8. The same opening .shown in an ey)hyra in order to illustrate its relations 

 to the remaining structures of the same. 



' ' 9. Cassiopea frondosa. 



" 10. The same (position assumed in floating). 



" 11. Ovary (shrunken) of X. il/crcMrras. 



" 12. Portion of the inner bell wall of the same medusa. 



" 13. L. Mercurius from oral side. 



a. Circular orifice, centrally placed, communicating between the 



stomach and the cavity situated above it. 



b. Opening leading from the cavity of the oral cylinder into the chymif- 



erous vessels of the arms. 



c. Cavity above the stomach. 



