Plate 31. 



Fig. 1. Tiaropsis rosea, young immature medusa. Tortugas, Florida, 



June, 1898. 

 Fig. 2. Tiaropsis rosea. One of the marginal sense-organs of the medusa 



represented in figure I. 

 Figs. 3 and 4. Tiaropsis rosea, young medusa with gonads beginning to 



develop. Figure 4, marginal sense-organ of the medusa shown in 



figure 3. Tortugas, Florida, July, 1898. 

 Fig. 5. Eucope parvigastra, mature medusa. Tortugas, Florida, July, 1898. 

 Fig. 6. Obelia sp. A sector of the bell-margin showing a radial-canal and 



a lithocyst. Agassiz Laboratory, Newport, Rhode Island, Sep- 

 tember 18, 1892. 

 Figs. 7 and 8. Obelia sp. Nassau Harbor, Bahamas, July, 1903. 

 Figs. 9 and 10. Clytia folleata, mature medusa. Nassau Harbor, Bahamas, 



June, 1903. See page 264. 

 Fig. 11. Tiaropsis diademata, mature male. Newport, Rhode Island, April 



24, 1897. 



See page 238 for description ot figures. 

 Drawn from life, by the author. 



