A. H. CLARK: THE CRTNOIDS OF THE INDIAN OCEAN. 211 



STIREMETRA ACUTIRADIA. 



Antedon acutiradia 1888. P. H. Carpenter/' Challenger" Reports, vol. 26 



Zoology, p. 113, pi. xi, figs. 3, 4. 

 Stiremetra acutiradia 1909. A. H. Clark, Proc. Biol. Soc. Washington vol. 22 



p. 15. 



Habitat. — Off Fiji. 



Depth. — 1350 fathoms. 



STIREMETRA BREVIRADIA. 



Antedon radiospina 1883. von Graff, Bull. ]\Ius. Comp. Zool. vol. 11, No. 7 



p. 133 (notnen nudum). 

 Antedon breviradia 1888. P. H. Carpenter, " Challenger " Reports, vol. 26, 



Zoology, p. 110, pi. iii, figs. 4, 5; pi. xi, fig. 5; pi. xix ; pi. xx, figs. 1, 2. 

 Antedon eversa 1888. P. H. Carpenter, "Challenger" Reports, vol. 26, 



Zoologyj pi. iii, fig. 5. 

 Stiremetra breviradia 1909. A. H. Clark, Proc. Biol. Soc. VV'ashington, vol. 22, 



p. 15. 



Habitat. — Off the Kermadec Islands. 

 Depth. — 630 fathoms. 



STIREMETRA CARINIFERA, Sp. nov. 



Description. — Centrodorsal large and columnar, the sides practically 

 parallel, 5 mm. in diameter and 3-5 mm. high interradially. The cirrus sockets 

 are arranged in ten columns, which are segregated in five pairs; there are three 

 or four cirrus sockets to a column. The two columns of each pair are separated 

 by a narrow ridge of moderate height ; the pairs, which are interradial in position, 

 are separated in the midradial line by deep V-shaped furrows as broad as the 

 adjacent cirrus sockets ; the central groove of these furrows is slightly rounded 

 off. The dorsal pole of the centrodorsal is fiattened, but the surface is more 

 or less irregular. 



Owing to the depth of the midradial furrows on the centrodorsal the sub- 

 radial clefts are practically obsolete, only their inner ends being visible as very 

 narrow and very shallow grooves. 



Cirri XXXV, 50-64 (usually 57 or 58) 45 mm. to 5(i mm. long; the seventh 

 or eighth (usually the latter) is a transition segment ; the first segment is very 

 short, the following gradually increasing in length and becoming about as long 

 as broad on the fifth and nearly or quite twice as long as broad on the eighth 

 (transition segment) ; the following segments gradually decrease in length, becom- 

 ing about as long as broad on the twelfth or thirteentli and after the twenty-fifth 

 about twice as broad as long. On the second after the transition segment 

 prominent median terminal spines begin to appear ; these gradually come t^ 



