MKDIS.E. 25 



distinctly of the type belonging to the Tiaridae. To place Cufdhliinn irelUon! among 

 the Cladonemidai because of the presence of filaments upon the tentacles when all its 

 other characters are distinctly those of the Tiaridtu would, in my opinion, be wrong. 



Placed amcjng the Cladouemidae is the remarkable Ctenavia ctenuphura of Haeckel. 

 It has filaments upon the tentacles somewhat similar to those of C'alablema u-eldmii ; 

 but it has an important character, namely, the presence of oral tentacles round the 

 mouth, a character which alone should be sutticient to place it in the family 

 Mari^clidie. 



The genus Zdnclea, sometimes called (Ji inniarin, which is tlic generic name of its 

 IIydroi<l, has tentacles provided with cnidophors situated on very fine thread-like, 

 contractile stalks. These are not at all like the filaments on the tentacles of Ctenaria 

 or Catahlenut tcelduiii. The Ilydroid Gemnviria belongs to the Syncorynidse, and 

 there is no reason, so far as I can see, why Zamlea should not be placed among the 

 Codonidae, not far away from the genus Sarsia, which is connected with the Ilydroid 

 Syticoryne. 



Pteronema is one of Pnjf. Haeckel's genera and its two species have not been 

 recorded since they were first described. Pteronema daricini has radial canals with 

 short diverticula, like those of a Catablema, so it may turn out to be one of the 

 Tiarida;. 



Mnesti-a is a curious parasitic Medusa. As the cnidophors on the tentiicles are 

 much like those of Zandea, it may belong to the same family. 



Halicharis is a Hydroid genus belonging to the Syncorynidse, but its Medusa is 

 not known. 



In the second sub-family, the Dendronemidae, there are three important genera : — 

 Eleutheriu, Cladoneiiia and Dendronnma. Both Clndimeinn and Dendronema have oral 

 tentacles round the mouth, a character also belonging to the Margelidaj. 



Eleutltvrin , better known under the name of Clavatella, is usually associated with 

 Cl'idonemn on account of both having suckers on the tentacles. The suckers are 

 specialized organs which liavc arisen and been perfected by a change in the habits of 

 the Medusae belonging to these two genera. Suckers also occur in certain genera 

 belonging ta the Trachomedusae. EletUherin is distinctly a crawling Medusa, and its 

 habits are not like tho.se of Cladonemn, which is an active swimmer, and only uses its 

 suckers for attachment. Except for the presence of suckers, there is nothing in 

 commfjn between Eleutheria and f'lndonema to justify their Ijeiug [)laced in the same 

 family. 



Zaticleopsis in & new generic name for Gevvnaiin dicluildiiKi of Dr. Mayer (1900), 

 and it is evidently an early stage without gonads. 



It .seems to me that the characters selected to distinguish the Cladonemidac from 

 the other great families ((Jodonidai, Tiarida), and Margelidse) of the Anthomedusae 

 arc more suitjiblc for generic or .specific characters, as they are ba.scd upon the structure 

 of the tentacles. iloreover, the structure of the tentacles does not belong to one 



