CAMPANICLAVA CLEODOR^E. 261 



coryne as understood in the restricted sense reqnired by our present views of the limitation of 

 hydroid genera. It includes a single species. 



*^* Campaniclava cleodoe/E, Gegciibaur, sp. 



Syncoryne cleodob*, — Gegenbaur, Generationswechselj p. 11, pi. i, figs. 3, 4. 

 Campaniclava cleodor.e, — AUman, in 'Ann. Nat. Hist./ for May, 1864. 



TROPHOSOME. — IlTDROKniZA branched, carrying the hydranths at distinct 

 intervals along its course. Hydeanths one half a line in height, with from five to 

 eight tentacles. 



GONOSOME.- — -GoNOPHOEES sessile, scattered on the hydrorhiza. Umbrella of 

 PLAXOBLAST, with a superficial band of thread-cells lying over each radiating canal, 

 and extending from the summit of the umbrella to its margin ; manubrium extending 

 to about half the depth of the umbrella-cavity, its mouth provided with four short lobes 

 set with thread-cells. 



Development of Gonosome. — November to March. 



Habitat. — Growing on the shell of living Cleodora friciinjndala. 



Bathijmetrical distribiitioii. — Surface zone. 



Locality. — Coast of Sicily, Gegenbaur. 



The two-tentacled medusa of Campanictava cleodora: is without doubt destined to undergo 

 changes before attaining maturity. It is almost certain that at least two additional tentacles 

 become developed, one from each of the intermediate marginal bulbs, as indeed the observations 

 of Gegenbaur, who obtained in the open sea free medusa; which he refers to this species, but 

 which were provided with four tentacles, go far to prove. 



In its habitat Campaniclava cleodora presents, as Gegenbaur notices, a feature of no little 

 interest, for it grows on the shell of a pelagic mollusc, so that not only do the medusje which 

 constitute its gonosome enjoy a free locomotive life, but the trophosome also spends its life upon 

 the open sea, always wandering over its surface like the active pteropod with wdiich it has associated 

 itself. 



Among forty specimens of Cleodora tricu.spidata observed by Gegenliaur no less than four 

 fifths of the whole carried a colony of Campaniclava on their shells. 



