;S SYSTEMATIC ZOOLO* . . 



SUBCLASS II. SCYPHOMEDUSiE 



The Scyphomedusae (Gr. er/cu<£o?, a cup, and Me'Soucra, 



Medusa) are known popularly as the large jellyfishes. There 

 are several points in which they differ from the Hydromedusae, 

 of which the most important, perhaps, is the absence of a true 

 velum. Further, the margin of the bell is not smooth, but 

 generally lobed more or less deeply, and the sense organs, eye>, 

 and otocysts, which here are modified tentacles, are usually pro- 



FIG. 64. A sea fan, greatly reduced. (Photographed from specimen by the author.) 



tected by a fold which projects over them from the margin of 

 the bell. A greater or less number of tentacles may be present 

 at the margin, and very frequently the manubrium bears four 

 tentacles, which are often long and greatly branched (Fig. 67). 

 Alternating with these four tentacles, there are, on the sub- 

 umbrella, four pockets or pouches, known as the subgenital 

 pits, because directly above them, on the four radiating canals 

 of the ccelenteron, lie the germ-glands. The germ-cells de- 

 velop from the entoderm as in the Anthozoa. Adjoining each 

 germ-gland on its central side in the ccelenteron is a series oi 

 threadlike processes, the gastric filaments, which are absent 

 in the Hydromedusae, and correspond to the mesenteric filaments 



