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



N.B. — Examples of this species have been distributed to several museums, and only 

 a few have come into my hands ; so that the first three of the measurements given above 

 must not be taken as indicating the whole range of variation throughout all the indi\dduals 

 which were dredged by the " Porcupine." 



Stem smooth and moderately robust, but of no great length. The upper part is 

 pentagonal with rounded angles ; but the lower portion of an old stem is almost perfectly 

 circular. Thirty to forty, and occasionally more, internodal joints with crenulated edges 

 which are less distinct below. Nodal joints enlarged, with sharp angular ridges which 

 stand out prominently between the cirrus-sockets. These are transversely oval, and 

 occupy the whole height of the nodal joint, which projects outwards over the upper edge 

 of the infra-nodal, while the supra-nodal is slightly grooved to receive the bases of the 

 stout cirri. These consist of about eighteen tolerably ec[ual, smooth, and thick joints, the 

 lowest of which are broader than their successors, especially in mature indi\4duals. 

 Terminal claw small, without an o^aposing spine. The lowest limit of the interarticular 

 pores is a little on either side of the fourth node. 



Basals pentagonal, but sometimes approaching the triangular, ^^'ider than high, and 

 forming a closed ring. The rays and their subdivisions in close lateral contact, the first 

 five or six joints after the distichal axillary having flattened sides. The two outer radials 

 united by s}^zygy. Fourteen to twenty-two arms, distichal axillaries being often absent, 

 and palmars very rare. Primary and secondary arms each of two joints united by syzygy ; 

 the first two brachials united in the same way, the epizygal bearing a pinnule. The arms 

 of about seventy smooth, oblong joints in which syzygies are very rare. 



The first pinnides c[uite short, consisting only of nine or ten joints, the lowest of 

 which are broad and flat, the later ones longer and more slender. The following pinnules 

 increase rapidly in size, and soon become long and tapering, consisting of about twenty 

 smooth, elongated joints, the lowest of which are slightly flattened. Disk completely 

 covered with a j)avement of small plates, as is the brachial perisome above the muscular 

 bundles. Arm-groove moderately wide, and bordered by a discontinuous series of 

 ambulacral plates. The pinnule-ambulacra have covering plates, but very ill defined 

 side plates. 



Colour grass-green, becoming white in spirit, which acquires a purplish-red tinge. 



Locality.— RM.^. "Porcupine," 1870. Station 17 ; lat. 39° 42' N., long. 9° 43' W.; 

 1095 fathoms; ooze; bottom tem^ierature, 39°'7 F. About twenty specimens. 



Also the "Talisman," 1883; off" the Morocco Coast: and again off Rochefort ; 

 lat. 45° 59' 30" N., long. 6° 29' 30" W. of Paris ; 1500 metres (800 fathoms). 



Remarhs. — This fine species was first obtained by Dr. Gwpi Jeff"reys during the 

 " Porcupine " expedition of 1870 ; and it was dedicated Viy him to his friend and colleague 

 Sir AVyville Thomson in the general account of the voyage which was published in the 



