480 THE AUSTRALIAN HYDROMEDUS^E, 



137. HETEEOPLON PLUM A. Allman. 



This Hydroid was dredged at Station 162 of the Challenger, 

 east off Moncoeur Island, Bass' Straits, in a deptli of 40 fathoms, 

 and has been described by Allman (I). 



20. GENUS. AGLAOPHENIA. McCrady. 



Shoots plumose, pinnate, often branched, rooted Ly a filiform 

 stolon ; alimentary Zooids with Hydrothecse, which are generally 

 toothed or lobed at the margin ; a median superior and two inferior 

 Machopolypes connected with each alimentary Zooid, no others 

 along the polypiferous ramules ; Polypostyles enclosed in corbulse, 

 or borne on specially modified pinnpe. 



The structure of several species of Aglaophenia has been investi- 

 gated by Weismann (2), and myself (3.) 



138. AGLAOPHENIA. KIRCHENPAUER1. Nov. sp. 

 Plate XV., figs. 20, 21, 22, 23. 



Stem smooth, divided by oblique joints into short internodes, each 

 of which bears a Pinna. The Pinnae are nearly opposite, long, 

 approximate and point to one side. Hydrothecoe cup-shaped, 

 margin slightly toothed, the lower part with two symmetrical 

 shallow indentures and slightly projecting, not adnate. The 

 inferior Nematophores barrel-shaped, the superior long and tubular 

 with a terminal and lateral apeiture. Half as long again as the 

 Hydrotheca and adnate to it only in its lower half. Corbulae 

 oval with seven serrated ribs. Gonothecse oval, stalked. 



This species attains a height of 5 cm. It was obtained at 

 Griffith's Point in Victoria. The specific name needs no 

 explanation. 



(1.) G Allmann. Report on the Hydroida. The Zoology of the Voyage 

 of H.M.S. Challenger. Part XX., p. 32. 



(2 ) A. Weismann. Die Entstehung der Sexualzellen bei den Hydro- 

 medusen. Seite 191. 



(3.) R. v. Lendenfeld. Ueber Wehrthicre find Nesselzellen. Zeitschr. f. 

 wiss. Zool. Band XXXVIII. , Seite 355. Translated into English Annals 

 and Magazine of Natural History, 5th Series. Nr. 71. 



