396 THE VOYAGE OF H.M.S. CHALLENGER. 



four similar spinelets, one of which is subequal to the furrow series, the others smaller ; 

 near the mouth there may be six spinelets in this series, and on the outer part of the 

 ray there are only three. This series may be disposed in an oblique line, but is usually 

 in an arc. 



The mouth-plates are comparatively large, and their armature consists of a marginal 

 series of about ten rather robust, cylindrical, obtuse spinelets, and a secondary or superficial 

 series of about the same number of more delicate and tapering spinelets, similar to those 

 on the adambulacral plates, arranged in a compact arc on the actinal surface of each plate. 

 A few additional smaller spinelets may also be present. 



The actinal plates bear a series or comb of four small spinelets, one of the median ones 

 being a little longer than the others, and all radiate slightly apart. Near the mouth there 

 may be five spinelets in a comb ; also one or two very small spinelets on each side, isolated 

 from the comb. The plates, which form regular transverse series, become very small as 

 they approach the margin, and the small combs of spinelets are very closely placed there, 

 one comb almost overlapping the next outermost in its own column or series. 



The marginal plates, which are very small but distinct and isolated, are somewhat in 

 the form of the blade of an old battle-axe, and they bear on their curved free margin a 

 double comb of about sixteen small subequal spinelets. These plates alternate with the 

 columns of abactinal plates ; and there is at the base of each of the plates just described a 

 second small plate with a comb of spinelets, which I regard as the representative of the 

 supero-marginal plate. 



The papular orifices are large and spiracle-like, margined by seven or more plates, each 

 of which bears a small comb of rather elongate spinelets directed over the opening. The 

 orifices, which are disposed in a single line on each side of the median radial line, are very 

 few in number and irregularly spaced. There do not appear to be more than five to eight 

 on each side of the radial ridge, and these may be arranged five or six near together near 

 the middle of the radial line and tolerably equally spaced, and then one or two nearer the 

 centre or nearer the extremity ; or there may be only two or three near together. The 

 occurrence of orifices on one side of the median ridge does not correspond with the 

 occurrence of orifices on the other side. 



Colour in alcohol, pellucid white. 



Locality. — Station 219. Off D'Entrecasteaux Reef, North of Admiralty Island. 

 March 10, 1875. Lat. 1° 54' 0" S., long. 146° 39' 40" E. Depth 150 fathoms. Coral 

 mud. Surface temperature 84° - Fahr. 



Remarks. — This species is a true Palmipes, but differs so essentially from either 

 Palmipes membra naceus or Palmipes rosaceus that no comparison is necessary. It is 

 an interesting addition to the small number of species of this singular genus. Unfor- 

 tunately the specimen collected by the Challenger is only a fragment. The whole starfish 

 must be an extremely elegant form, remarkable for its delicacy and transparency. 



£ 



