Mi 



MEDUSAE OF THE WORLD. 



Tabular Description of the Medusa of Zanclea. 



GENERIC CHARACTERS. 



Cladonemidae with 4 simple radial-canals, and 2 to 4 radially situated tentacles which give 

 rise to filiform, knobbed, nematocyst-bearing side branches. The gonad is developed upon the 

 sides of the stomach. There is no apical brood-pouch above the stomach. There are merid- 

 ional lines of nettle-cells over the exumbrella. There are no tentacular ocelli. The hydroid 

 is Gemmaria Allman, 1871. 



In 1857, McCrady founded the genus Gemmaria for a Zanclea-\ike medusa with only 2 

 tentacles. Vanhoffen, 1891, and Browne, 1905, have observed that the 2-tentacled young of 

 other species of these medusae often becomes 4-tentacled when adult, and according to Browne, 

 1905, "Gemmaria" implexa may become mature with 2 or with 4 tentacles. It is evident, 

 therefore, that there are no definite generic distinctions between Zanclea and Gemmaria, the 

 "Gemmaria" condition being only a developmental or retarded phase of Zanclea. 



Murbach and Nutting have erroneously applied the name "Corynitis" to a 2-tentacled 

 medusa of Zanclea. Apparently these authors had not seen the medusa of Corynitis, which is 



