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Genus Zygometra A. H. Clark. 

 Zygometra microdiscus (Bell). 

 One specimen was secured, at Mermaidsk, northwestern Australia. 

 It has about eighty-five arms, and is deep purple in colour, the cirri 

 and enlarged lower pinnules being lighter. 



Zygometra elegans (Bell). 



Four specimens from Mermaidsk, northwestern Australia, appear 

 to belong to this species as described by Professor Bell; they possess 

 thirty-five to eighty arms; the II Br series are 4 (3 + 4), the III Br 

 and IV Br usually 2, more rarely 4 (3 + 4). In cases where III Br 

 4 (3 + 4] series are developed they are usually external in relation to 

 the I Br series as in Himerometra, and there is also usually one more 

 axillary on the inner side of each II Br series than on the outer, also 

 as in Himerometra\ furthermore, the brachials are exceedingly short 

 and discoidal as in Himerometra, so that, at a casual glance, it might 

 very well be mistaken for a member of that genus. 



I cannot agree with Dr. Carpenter in regarding his fluctuant 

 as a synonym of this species. Judging from a very large series from 

 Singapore and the Philippine Islands, fluctuans has uniformly about 

 thirty arms with wedge-shaped brachials, and comparatively short cirri 

 with not more than thirty-five joints; it is a smaller and more delicate 

 species, with the III Br series always 2, developed internally, and bears 

 a very close resemblance to the species of Hete?'ometra . 



Genus Dichrometra A. H. Clark. 

 Dichrometra protectus (Liitken). 



Two specimens of this species from Bougainville Island, in the 

 Solomon group , agree perfectly with a series from Singapore in the 

 collection of the University of Copenhagen. Each has forty arms and 

 is dark brown in colour. 



Another specimen was collected on the coral reef at Salawatti, 

 near New Guinea. 



Dichrometra palmata (Müller). 



Two specimens from the coral reef at Salawatti, off the north- 

 western corner of New Guinea, agree perfectly with Dr. Hartlaub's 

 excellent description of the species. One has thirty arms the other 

 thirty-four, in each about 100 mm long; the cirri are XXVIII, 27—28, 

 20 mm long, and XL, 24—27, 16 mm long respectively; the polar area 

 of the centro-dorsal is flat, 3 mm to 4 mm in diameter. The colour is 

 dull pinkish, Motched with bluish gray. 



