160 MR W. PERCY SLADEN ON THE 



of being rooted in membrane and rather thickly invested at their base, which 

 gives the spine-groups a larger and somewhat more expanded character than 

 usual in shallow water specimens. The three examples from Station 10 are 

 much smaller, and their spinulation is very minute and scanty, seldom more 

 than two to four spinelets being present in a group. The effect of this is 

 perhaps most striking in the armature of the adambulacral plates, where the 

 group of spines external to the furrow-series becomes abnormally small and 

 insignificant. The comparative length of the ray and its almost uniform 

 breadth is very conspicuous in conrparison with small specimens of similar size 

 of the ordinary form, in which the ray is proportionally shorter in the young 

 stage than in the adult. The colour in alcohol of the specimens under notice is 

 a dirty greyish- brow 7 n. 



Considering the known variability of the species, I do not at present feel 

 justified in doing more than placing on record the character of the variation 

 above noted. If a larger supply of material should ultimately necessitate the 

 nominal recognition of this form as a deep-sea variety, it might appropriately 

 be called cylindrella. 



11. Zoroaster fulg ens, Wyville Thomson. (Plate XXVI. figs. 9-11.) 



(Zoroaster fulgens, Wyv. Thorns. (1873), The Depths of the Sea, p. 154, fig. 26.) 



Station 11. August 28, 1882. Lat. 59° 29' N., long. 7° 13' W. 

 Depth, 555 fathoms ; bottom temperature, 45°'5 Fabr. A young 



example. 

 Station 13. August 31, 1882. Lat. 59° 51' 2" N., long. 8° 18' W. 

 Depth, 570 fathoms ; bottom temperature, 45°'7 Fahr. 



A brief description and a woodcut of this handsome starfish were given by 

 Sir Wyville Thomson in the work cited above. As no detailed description of 

 the species has yet been published, the following may not be unacceptable : — 



Rays five. 11 = 125 to 130 mm.; r=14 to 15 mm. 



Rays very long, narrow, subcylindrical, and tapering throughout to a finely 

 pointed extremity ; arched on the abactinal surface, and tumid on the actinal 

 surface on either side of the furrow, which is deeply sunken. Interbrachial 

 angles acute. Breadth of a ray at the base 17 mm. 



The disk is rather higher than the. rays and slightly tumid. The calcareous 

 skeleton of the whole test is formed of suboval or subhexagonal plates, disposed 

 in perfectly regular longitudinal and transverse series. The following is the 

 arrangement they present. Surrounding a dorso-central and five small radially 

 placed plates arc five large plates interradial in position; and outside and 

 alternating with these are five similar but rather smaller radially placed plates.* 



It will Ik: noted that these plates represent in a remarkable manner the dorso-central, the under 

 basals, the basals, and the radials respectively of the crinoid calyx. 



