146 CAMPANULAUIID^E. 



deep water. Like other Campannlarians it shows a pre- 

 dilection for the red weeds. The ribbon-like leaves of 

 Zostera marina are also frequently profusely covered with 

 it ; indeed it is generally distributed and adorns with its 

 crystal cups and ringed pedicels the most various marine 

 substances. 



[Belgium ; Brittany ; Norway (Van Ben.) : coast of 

 France generally (Lacaze-Duthiers) : "from Grand Ma- 

 nan Island, at the extreme eastern coast of Maine, all 

 along the New England coast to Vineyard Sound, south 

 of Cape Cod " (Agassiz).] 



Genus OBELIA, Peron fy Lesueur*. 



LAOMEDEA, Larnouroux, Bulletin Philomatique, 1812. 



CAMPANULARIA (in part), Lamarck, An. s. V. (2nd ed.) ii. 129. 



MONOPYXIS, Ehrenberg, Corall. roth. Meer. 73. 



THAUMANTIAS (in part), Forbes, Brit. Naked-eyed Medusae, 41. 



EUCOPE (in part), Gegenbaur, " Syst. d. Medus.," Zeitschr. f. wissenschaft. 



Zool. Tiii. 241 (the free zooid); Agassiz, N. H. U. S. iv. 351. 

 OBELIA, M'Crady, Gymnoph. Charleston Harb. ; Agassiz, N. II. U. S. iv. 351 ; 



Allman, Ann. N. H. for May 1864. 



GENERIC CHARACTER. Stem branching, plant-like, rooted 

 by a creeping stolon ; hydrothecce campamilate, without 

 operculum ; gonothec& borne on the stems and branches ; 

 reproduction by free medusiform zooids. 



Gonozooid : Umbrella (at the time of liberation] depressed 

 and disk-like ; manubrium short and quadrate ; radiating 

 canals 4 ; 'marginal tentacles numerous (increasing in num- 

 ber with age) , prolonged at the base and projecting inwards ; 

 lithocysts 8, two in each interradial space, borne on the in- 

 ner side of eight of the tentacles near the base. 



M'CRADYf was the first to restore the name Obelia, con- 



* "Histoire gen6rale des Meduses," Ann. du Museum, xiv. 43, 1809. 

 t Gymnophthalmata of Charleston Harbour, p. 94. 



