772 " THETIS " SCIENTIFIC RESULTS. 



Differential Characters. — This species is readily distinguished 

 from D. articulata by its fewer cirrus segrDents which are strongly 

 carinate instead of spiny distally, by having Pg considerably 

 longer tlian Pg, and the proximal pinnules on tlie outer side of 

 tlie outer arms of each post-radial series markedly larger than 

 those on the inner side of the outer arms or on the inner arms. 



Australian Records. — Torres Strait ; Queensland ; Bowen and 

 Port Denison, Queensland. There is a dry specimen in the 

 British Museum (labelled Antedon articulata) from Port Essing- 

 ton, Queensland, and there is a specimen in the Paris Museum 

 from Thur.sday Island, 



Distribtitio'n. — Marshall Islands to northern Australia, south 

 on the east coast to Port Denison, Queensland. 



Family COLOBOMETRID^, ^. ^. Clark. 



Genus C E N O M E T R A, A. H. Clark. 



Cenoinetra, 1909, A. H. Clark, Proc. Biol. Soc. Washington, vol. 

 22, p. 8 (HiMEROMETRA UNICORNIS, A. H. Clark, 1908). 

 Differential Characters. — The cirri of the species of Cenometra 

 are composed of vei'y short subequal segments, of which those in 

 the outer portion bear two dorsal tubercles or spines each, j)laced 

 side by side : Pg is greatly enlarged, abruptly larger than any of 

 the other pinnules, and is strongly curved outward in the direc- 

 tion of the arm tip. 



Range. — Mauritius and Ceylon to northern Australia, thence 

 northward to the Philippine Islands and the Gulf of Tonkin. 



CENOMETRA CORNUTA, sp. nov. 



Antedon, sp. (near raacronema), 1894, Bell, Proc. Zool. Soc, 

 1894, p. ^%i {North-west Australia). 



Description. — Cirri XIV, 35-37, about 20 mm. long ; the cirri 

 are rather slender, and are composed of short segments, none of 

 which are less than twice as broad as long ; the proximal seg- 

 ments are flattened dorsally ; in the outer half of the cirri the 

 segments bear dorsally a pair of tubercles with their apices well 

 separated. 



There are, in the type, twenty-six arms about 110 mm. long; 

 the lateral processes on the division series are broad with trun- 

 cated or roundedly incised outer margins. 



Pg is very stout and very strong!}' curved, with 11-14 (usually 

 12) segments, most of which are about as long as broad ; on the 

 distal side the distal ends of the segments are strongly everted 

 and serrate ; this aversion is well marked even on the second 



