ALCYONAREANS. — BRIGGS. 83 



Locality. — Six miles 8. 30° E. of Brush Island, New South 

 Wales, 65 fathoms. 



Distribution. — Hitherto known only from specimens ob- 

 tained l)y the " Thetis " otf the coast of New South Wales at 

 the following localities : — Station 13. off Cape Three Points, 

 41-50 fathoms ; Station 17, off Broughton Island, 29-48 

 fathoms ; Station 34, off Port Jackson, 39-36 fathoms ; 

 Station 48, off Wollongong, 55-56 fathoms (Thomson and 

 Mackinnon). 



Plumaeella australis, sp. nov. 



(Plate iv., fig. 3 ; Plate x. ; Plate xi., fig. 2.) 



This new species is represented by both dried specimens 

 and others in spirit. 



The colonies are tyisically feather-like. In the largest 

 specimen there is a slightly flattened stem, 5mm. in thick- 

 ness. The colony has a height of 43cm., with a spread of 

 32-5cm. across the expanded portion. The basal attach- 

 ment is lacking. The branching is confined strictly to one 

 plane. The stem gives off strongly flattened branches at 

 rather Avide intervals, which bear on each side a row of 

 alternating tAvigs. These twigs occasionally branch in the 

 same pinnate manner, but usually they remain simple. The 

 longest twigs are 8cm. in length, with a diameter of 2nim. 

 There are eight twigs in each row in a length of 5cm. 



Some of the colonies show the basal portion, Avhich con- 

 sists of a well-develojsed calcareous expansion about 20mm. 

 in thickness. From this there rises a cylindrical stem, 7mm. 

 in diameter, which soon becomes compressed with its long 

 axis lying in the same plane as that of the colony. 



The polyps are arranged bilaterally on the stem and 

 branches ; on the twigs their arrangement is also lateral, 

 but there is a tendency, in some instances, to encroach on 

 the middle line. They are arranged in a double roAv along 

 each side on the twigs, those of one row alternating with 

 those of the other on the same side. The polyps have an 

 average length of -75 mm. 



Scattered among the normal-sized polyps in some of the 

 colonies, there are a few large SA\-ollen polyps of about t\\ice 

 the size of the others ; these contain reproductive l)odies. 



