Notes on some Hydromedusae from the Bay of Napley. 581 



JPodocoryìie conciiicola (Philippi), in part. 



Since the originai description of Podocoryne carnea by Sars ^ in 

 1846 its distribution has been recorded over a large portion of the 

 nortliern Atlantic on both eastern and western coasts, and several 

 new species bave been described. 



During- tbe spring and summer of 1903 the present writer bad 

 occasion to examine several colonies of wbat appeared to be per- 

 fectly typical species of Podoconpic carnea Sars. An examination 

 of the medusae, large numbers of which were set free in the aqua- 

 ria, showed them to dift'er from this species in the rather remarkable 

 fact that they possessed only four marginai tentacles at birth, 

 whereas medusae of the other species bave imiformly eight at the 

 tioie of birth or very shortly foUowing. So far as I am aware, only 

 oue species of Podocoryne has a medusa whose tentacles are only four 

 in number, namely, P. acideata Rud. Wagner, and in this species 

 ali are quite rudimentary and continue so. The specimens bere 

 under consideration seem to bave four tentacles, and only four. 

 Medusae were kept in the aquaria for several days, indeed as much 

 as a week, during which time the sexual products were matured 

 and discharged, but in not a single case was there the sign of 

 additional tentacles. I was, moreover, assured by Dr. Lo Bianco, 

 who is familiär with the fauna of this region, that this medusa 

 never has more than the four primary tentacles, so far as he bad 

 observed. 



In bis account of British Hydroid Zoophytes Hincks- includes 

 among the species of Podocoryne, areolata, originally described by 

 Alder as Hydractinia areolata, whose medusae are characterìzed by 

 the presence of from one to three unecjually developed tentacles in 

 each interradial interval, in additiou to the four primary perradial 

 tentacles. So far as I am aware this is the only known species 

 whose tentacles number more than eight. 



Haeckel^ under the generic name Dysmorpliosa describes four 

 species, namely, carnea Sars, fidgurans A. Agassiz, minima Haeckel, 

 and octostyla Haeckel, and these are ali characterìzed by the pre- 

 sence of 8 tentacles, the interradial group usually arising slightly 



1 Fauna Littor. Norvegiae 1846. 



2 British Hydroid Zoophytes. London 1868. 



3 Das System der Medusen. Jena 1879. 



