214 THE VOYAGE OF H.M.S. CHALLENGER 



Locality. — Station 18(5. In Torres Strait, off Cape York. September 8, 1874. Lat. 

 10° 30' 0" S., long. 142° IS' 0" E. Depth 8 fathoms. Coral mud. Surface temperature 

 77° -2 Fahr. 



Remarks. — Astropecten zebra is distinguished from Astropecten velitaris by the three 

 or four comparatively large flattened spines on the supero-marginal plates on each side of 

 the median interradial line, and by the presence of the well-developed pedicellariae ; and it 

 is distinguished from Astropecten fragilis by the single lateral spine, and by the spinelets 

 in the aboral series on the infero-marginal plates increasing in length as they approach the 

 margin. The armature of the adambulacral plates is also different. 



11a. Astropecten zebra, var. rosea, Sladen. 



Astropecten zebra, var. rosea, Sladen, 1883, Journ. Linn. Soc. Lond. (Zool.), vol. xvii. p. 263. 



The examples of Astropecten zebra from Station 186 are very constant in their 

 characters. The specimens from Station 187 (three in number) present some variation. 

 In colour they are a rosy brown, approaching madder-brown, and the markings are 

 dark brown. The actinal surface is a delicate rosy pink, and the tube-feet are a rich 

 scarlet. The rays are slightly broader, and taper rather more rapidly at the tip. Only 

 the innermost two or three supero-marginal plates bear spines, which are smaller and almost 

 invisible excepting the innermost. The small spinelets on the aboral margin of the infero- 

 marginal plates do not form the continuous line noted in the specimens from Station 186, 

 but are wanting in the median portion, thus leaving the spinelet near the adambulacral 

 plates isolated, and the spinelet near the lateral spines is relatively larger and might almost 

 be counted along with the laterals. 



Locality.— Station 187. In Torres Strait. September 9, 1874. Lat. 10° 36' 0" S., 

 long. 141° 55' 0" E. Depth 6 fathoms. Coral mud. Surface temperature 77°"7 Fahr. 



12. Astropecten velitaris, von Martens. 



Astropecten velitaris, von Martens, 1865, Archiv f. Naturgesch., Jahrg. xxxi., Bd. i., p. 360. 



Localities. — Amboina. Depth 100 fathoms, 15 to 25 fathoms. 



Admiralty Islands. Depth 16 to 25 fathoms. 



Remarks.- — Dr von Martens when describing this species suggested, with his customary 

 care and foresight, that owing to the small size of his type (R = 16 mm.) it might possibly 

 be thought that Astropecten velitaris would ultimately prove to be the young phase of 

 some other species, such for instance as Astropecten armatus, Miiller and Troschel (i.e., 

 Astropecten polyacanthus). In support of the view that it is a distinct species, or at any 

 rate not the young of Astropecten polyacanthus, I may here mention that small examples 

 of Astropecten polyacanthus from Port Jackson, the smallest measuring about R = 8 to 9 





