THE RECENT CRINOIDS OF AUSTRALIA CLARK. 771 



f P2 is about 22 mm. long, very slender and delicate, flagellate, 

 soft, with forty -three segments which are only slightly longer 

 than broad ; Pg is similar to Pg, but tlie following pinnules are 

 shorter ; Pj^ is 14 ram. and P4 10 mm. in length ; there is but a 

 slight difference in basal stoutness between the earlier pinnules, 

 but Pg and P3 taper much less rapidly than the others. 



This species is very close to D. artictdata, and further investi- 

 gation may show that the two are really identical. 



DICHROMETRA GYGES {Bell). 



Antedon gyges, 1884, Bell, Rep. Zool. Coll. H.M.S. "Alert," p. 



160, pi. xii., figs. B, Ba, b (Thursday Island). 

 Dichrometra gyges, 1909, A. H. Clark, Proc. Biol. Soc. Wash- 

 ington, vol. 22, p. 13. 

 Differential Characters. — Dichrometra gyges has Pg not much 

 longer than Pj ; the cirri resemble those of D. regincB, but have 

 a slightly greater number of segments. There is a possibility 

 that it is the same thing as the species known as Dichrometra 

 tenera. Like D. regince this species is badly in need of rede- 

 scription. 



The only known specimen of Dichrometra gyges was collected 

 by the " Alert " at Thursday Island, in 3-4 fathoms. 



Remarks. — In the type of this species, which I examined at 

 London, the cirri are xxxv, 24-29 (usually 28), 20 mm. to 

 25 mm. long ; from the eleventh onward the segments are 

 strongly carinate, or are supplied with broadly rounded dorsal 

 spines. 



There are forty-one (thirty-seven, plus four lacking) arms 

 80 mm. long. 



P2 is the longest, but is slender, resembling P^ ; Pg is slender 

 and weak, not nearly so large as P^ ; the basal segments of the 

 earlier pinnules are more or less carinate. 



This species is nearly related to D. tenera, of which it may 

 eventually prove to be a synonym. 



DICHROMETRA TENERA (Hartlaub). 



Antedon teller, 1877, Liitken, Mus. Godefl:r. Cat., vol. 5, p. 100. 

 Antedon tenera, 1890, Hartlaub, Nachr. Ges. GoLtingen, Mai, 



1890, p. 180 (Queensland ; Torres Strait). — 1891, Nova 



Acta Acad., German, vol. 58, No. 1, p. 66 (Qaeetisland ; Fort 



Denison ; Torres Strait). 

 Dichrometra tenera, 1909, A. H. Clark, Vidensk. Medd. fra den 



Naturhist. Foren. i Kobenhavn, 1909, p. 173 (Bowen). 



