BY R. VON LENDENFELD, PH.D. 351 



5. EUDENDRIUM GENERALIS. Nov. spec. 

 Plate VI. 



On stoues, near low water mark, this Hydroid is very abundant 

 in Port Phillip. Rising from an anastomosing stolon, the stum 

 attains a height of 18 mm. The Peiisarc of the stem is not much 

 thicker than that of the branches, and only slightly darker. The 

 Perisarc is in its greater part cylindrical, and appears annulated 

 only at the proximal ends of branches and stem. In size and 

 general appearance it might be taken for Eudendrium capillare 

 Alder. The Trophosome possesses one verticil of twenty-four 

 filiform tentacles, a very large and moveable proboscis, which 

 mostly appears slightly dilated laterally and a broad and short 

 body. The ring of gland cells at the base of the Trophosome is 

 very well marked. 



Weismann (1) has discovered that in Eudendrium racemosum 

 the Hydranths possess large processes which he terms Cnidophors. 

 Such structures are absent in our species. 



Allman (2) alludes to an external difference between the male 

 and female Polypostyls in some species of Eudendrium. Such a 

 difference is still more marked in our Eudendrium generalis and 

 I have selected the specific name to express this peculiarity. 

 Our species is distinguished from those desmbed by other 

 authors by its small size. E. ramosum Linne, E. rameum Pallas, 

 E. dispar Agassiz, E. annulatum Kormann, are vexy much larger. 

 The male Polypostyls in Eudendrium capillare bear clusters of 

 two-chambered scrota, whilst in our species they are not in 

 clusters, and only contain a single pouch. E. arbuscula Wright 

 " forms a bushy tree" and also bears a cluster of scrota on the 

 male Polypotyls. In Eudendrium insigne, Hincks again, the 

 perisarc is annulated throughout; the same is the case with E. 

 vaginatum, whilst in E. tenue A. Agassiz, the scrota are in 

 clusters. 



(1) A. Weismann. Ueber ein eigenthiimliches Organ bei Eudendrium race- 

 mosum Cav. Mittheilungen aus der Zoologischen fetation in Neapel. Band 

 III. Seite 1. 



(2.) Allman. A Monograph of the Gymnoblctstic or tubular ian Hydroids, 

 Vol. II, p. 332 ff. 



