SYNCORYNE FRUTESCENS. 281 



Locality/. — Loriciit, Dujardiii. 



The Si/ncoryiw decipiens possess an liistoric interest in l)eing a species which had afibrdcd 

 material tor some of tlie earliest observations on the production of free medus;e hy the fixed 

 trophosonie, for it uas studied by Dujardin, who lias described it in his well-known memoir 

 as presenting an cxami)le of this phenomenon. 



It is not easy, however, to collect from Dujardin's description characters suilicient for a 

 satisfactory diagnosis of the species ; those given above may be gathered from his memoir, and 

 are probably sufficient to secure this species from being confoiuidcd with any other. 



Dujardin describes its medusa, which he names "Sthenyo" as undergoing some time after 

 its escape from the tropliosome, and while still in the confiuement of his vases, certain remarkable 

 changes, which consist chiefly in a complete retroversion of the umbrella. The changes noticed 

 by Dujardin would seem to be very similar to those which I have myself observed in the nearly 

 allied Sjncortjnc puhhella. (See above p. 203). 



7. Syncoryxe rRUTESCExs, Allmaii. 

 Plate VI, figs. 4—6. 



TROPHOSOME. — Hyduocaulus much branched, rising from a creeping stolon, 

 and attaining a bciglit of from one to tv^•o inches ; perisauc sraooth. Hydranths 

 oval, witb about fourteen tentacles. 



GONOSOME. — Plaxobeasts springing by short peduncles from the body of the 

 hydranth at the proximal side of the tentacles ; transverse and vertical diameters nearly 

 equal ; umbrella studded with scattered tln-ead-celis ; marginal tentacles with slightly 

 elevated clusters of thread-cells, which render it verucose, but not properly moniliform ; 

 ocellus distinct ; manubrium with the mouth surrounded by a ring of thread-cells. 



Colour . — Hydranth light [)ink ; manubrium of medusa, and basal bulbs of mai'ginal tentacles 

 light brownish red. 



Bevdopment of Gonosome. — October. 

 Habitat. — On floating timber. 

 Locality/. — Kingstown, Dublin. 



1 have onlv once met with this species, which approaches in uuuiy respects to the S^ncoiyitc 

 decipiens of Dujardin. From this species it is chiefly distinguished by its more oval Iiydranths 

 and their more numerous tentacles, as well as by the less moniliform disposition of the groups of 

 thread-cells in the marginal tentacles of the planoblast. 



It was found attached to floating logs in a reservoir exposed to the tide, and constantly 

 supplied Ijy sea-water from Dublin Bay. 



