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



series is a line of three short papilliform spinelets parallel to the furrow, rather wide apart, 

 and of which the two outside sjnnes often aj^pear as if they belonged to the furrow series. 

 Behind these is a second and similar longitudinal series of three spines, the middle one 

 being often longer than the others ; and these are followed by three or four smaller papillae, 

 completing the armature of the plate. The furrow series have a decidedly palmo-radiate 

 appearance, and the spines of the external series have a tendency to incline at a slight 

 angle towards the next adjacent adambulacral plate. 



The actinal interradial areas are comparatively small and are ornamented with short 

 papilliform granules, which appear to be arranged rather widely apart round the margins 

 of the plates ; sometimes one or more papillae are present in the middle of this circlet, 

 and occasionally one is slightly larger than the rest. Consequent on this arrangement 

 the individual plates are more or less defined, but are not distinct ; the spinulation is by 

 no means crowded. 



The pair of mouth-plates form a subelliptical or widely fusiform outline. Each plate 

 bears a straight line of about ten short papilliform spinelets running parallel to the 

 median suture, and a similar number on the opposite margin of the plate which con- 

 sequently form a curved series ; one or two additional spinelets may be present on the 

 intermediate area of the plate. The marginal spines are about equal in length to 

 the adambulacral spines, but are rather more robust. 



Colour in alcohol, a yellowish ashy grey. 



Locality. — Station 49. Off the coast of the United States, south of Halifax, Nova 

 Scotia. May 20, 1873. Lat. 43° 3' 0" N., long. 63° 39' 0" W. Depth 85 fathoms. 

 Gravel and stones. Bottom temperature 35°'0 Fahr. ; surface temperature 40°'5 Fahr. 



Remarlcs. — This species is allied in many respects to Pseudar chaster tessellatus. The 

 rays, however, are more tapering, the abactinal area is less inflated, the paxillae though 

 smaller are composed of more numerous spinelets, the marginal border formed by the 

 supero-marginal plates is broader, the covering of the infero-marginal plates is more 

 squamiform, and the definite single line of pointed spinelets which occurs in Pseudar chaster 

 tessellatus is not present. There is no large prominent spine on the outer part of the 

 adambulacral armature as in the South-African species. 



Genus Aphroditaster, Sladen. 

 Aphroditaster, Sladen, in Narr. Chall. Exp., 1885, vol. i. p. 612. 



Disk rather small. Rays elongate, tapering. Interbrachial arcs well rounded. 



Marginal plates broad, forming a well-rounded margin ; intermediate abactinal area 

 narrow and sunken. Supero-marginal plates with rounded granules, infero-marginal plates 

 with small, uniform, conical-pointed, adpressed (squamiform ? ) spinelets. No prominent 

 spines on either series. 



