Australian Hydroiih. \'i^ 



angle (al)Oiit 75 deg. to 80 deg.), and a little directed towards the- 

 front ; nodes transverse or scarcely oblique, indistinct. 



Hydrothecae borne toAvards the front of the hydrocladia, with 

 which their longest diameter is parallel, a slight constriction near 

 the base on the adcauline side, continued- into a slight transverse- 

 fold ; an anterior intrathecal ridge projecting downwards from 

 between the front of the aperture and the mesial sarcotheca more 

 than half-way through the cell ; aperture at a small angle Avith the 

 hydrocladiuiu. sub-crenate. sub-plicate, each side forming an 

 angular lobe, front entire, a rounded lobe or an erect tooth behind. 

 Hydrothecal internode Avith tAA'o divergent septal ridges, one nearly 

 opposite the rudimentary posterior ridge, the other at the base of 

 the lateral sarcothecae ; generally a third midAvay betAveen them. 



Mesial sarcotheca adnate to the front of the hydrotheca nearly 

 as far as the aperture and mainly rising from it, free part variable- 

 in length, slightly tapering, projecting forAvard at a varying angle, 

 Avith distinct terminal and inferior apertures and a small orifice 

 opening into the hydrotheca. Lateral sarcothecae conical or 

 tubular, either adnate and directed upwards, or large, free and 

 projecting doAvnAvaids from the hydrotheca; terminal and lateral 

 apertures distinct. Cauline sarcothecae similar to the laterals, but 

 Avider, tAA'o at the base of each hydrocladium. 



(Gonosome 1 



Colour, bright broAvn. 



Hn}>. — Port Darwun Telegraph Cable : ofE Cumberland Island. 27 

 fathoms (Busk) : Bay of Amboyna. 80 metres (A. disjuncta, Pictet). 



This species, like A. hrevirostris. Avas insufficiently described by 

 Busk, and remained unidentified until 1909, AA'hen Billard examined 

 Busk's type in the British Museum, and found its structure to agree 

 AA'ith that of L. phoernceus. But the habit is different; Busk say& 

 that the branches are at right angles to the stem, and that the 

 habit closely resembles that of A. hrevirostris (where the hydrocladia 

 also form a Avide angle Avith the rachis), while in all the varieties, 

 of L. phceniceus observed by me the branches, and also the hydro- 

 cladia, are set at angles of about 45 deg. L. auritus may 

 therefore be described as having the habit of A. hrevirostris with 

 the minute structure of L. phceniceus, and this description applies 

 to a small specimen which, I have had for many years, but which 

 I had ahvays hesitated to assign to L. phoeniceux (notAvithstanding 

 the similarity of the hydrothecae). on account of the different habit. 

 It Avas still in the monosiphonic stage, and, therefore, unbranched, 

 and Avas collected from the Port DarAvin cable. Avhcro it Avas growing- 



