HETEROCORYDLE CONYBEAREI. 307 



HETEROCORDYLE, Allman. 



Name.— Yxom steooc, dissimilar, and /vopou'Ai,, a club; in allusion to tlic two lands of club- 

 shaped zoids, the hydranths and the blastostylcs. 



TROPHOSOME. — Htdrophyton composed of a simple or branching hydrgcaulus 

 rooted by a creeping filiform hydroehiza, the whole invested by a chitinous pesisarc. 

 Hybbanths fusiform, with a single circlet of filiform tentacles round the base of a 

 conical liypostome. 



GONOSOME. — Sporosacs borne upon blastostyles. 



The genus Hefcrocordi/le has been founded for a hydroid discovered on the southern coast 

 of Ireland. Its trophosome is that of Dicorym, but from this genus it is entirely separated by 

 its very different gonosome. 



Heterocordyle Conybearei, Allman. 



Plate X, figs. 4—7. 



Hkterocordyle Conybearei, — Allman, in Ann. Nat. Hist, for May, 1864, and July, 1861, 



pi. ii. Hincks, Brit. Hydr. Zooph., p. 107, pi. 

 xviii, fig. 2. 



TROPHOSOME. — Hydrocaulus consisting of numerous stems crowded upon the 

 creeping hydroriiiza, some much branched, and attaining a height of about four 

 lines, others shorter and simple ; perisarc transversely corrugated, extending for a 

 short distance over the base of the hydranth. Hydranths with about twelve 

 tentacles, usually held straight in extension, with the alternate ones elevated and 

 depressed. 



GONOSOME. — Blastostyles club-shaped, borne on the summit of very short erect 

 processes, which spring from the UYDRORmzA, and are invested with a chitinous peri- 

 sarc ; distal extremity of blastostyle thickly set with thread-cells. Sporosacs numerous, 

 nearly sessile, densely crowded, commencing a little behind the distal extremity of the 

 blastostyle, and thence extending to within a short distance of its base. 



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