446 THE VOYAGE OF H.M.S. CHALLENGER. 
“Knight Errant” dredgings, can I recognise an identity with the specimens described by 
the eminent Norwegian naturalists. Judging from the description above cited, it seems to 
me that the variety septentrionalis occupies an intermediate position between the typical 
form of Crossaster papposus and the Solaster afjinis of Danielssen and Koren, and this 
circumstance previously led me! to express the opinion that the latter form might be a 
locational variety of the type of Crossaster papposus. 
2. Crossaster penicillatus, n. sp. (Pl. LXX. fig. 5; Pl. LXXIT. figs. 9 and 10). 
Rays nine. R=34 to 36 mm.; r=12 mm. R<3 7. Breadth of a ray near the 
base, 6 mm. 
Rays narrow and rather attenuate, more or less arched abactinally and with a tendency 
to be carinated on the outer part. Disk slightly inflated. Interbrachial arcs rounded. 
Abactinal area with small delicate plates forming a reticulated network with wide 
meshes, bearing small, rather widely spaced paxilliform tufts of spinelets, articulated on a 
tubercular base. The larger paxille on the disk and at the base of the rays have a crown 
of about ten or more spinelets, five or six being long and needle-like, the rest much 
shorter. From two to four large isolated papule occur in the meshes. No definite order 
of arrangement is discernible in the disposition of the paxille. 
The marginal plates (the representatives of the infero-marginal series) are large and 
very widely spaced, and resemble greatly enlarged paxille. The base is thick and large, 
slightly compressed (the major axis being placed obliquely in relation to the axis of the 
ray) and bears a crown of about twelve to fifteen needle-like spinelets. 
The armature of the adambulacral plates consists of two series of spinelets. (1.) A 
furrow series of four or five elongate spinelets united for a short distance at their base 
by a delicate membranous web, and forming a fan directed over the ambulacral furrow. 
(2.) A transverse lineal series of seven or eight long robust spines, longer than those of the 
furrow series, which may form either a straight or a slightly curved line on the actinal 
surface of the plate. These spinelets diminish in size at the outer end of the series, and 
are united for a short distance at their base by a delicate membranous web. 
The mouth-plates are large and the united pair have a spade-shaped outline. Their 
armature consists of a marginal series of about nine elongate spinelets on each plate, the 
innermost one being larger and more robust than the others, which diminish a little in 
size as they recede from the mouth, and are rather smaller than the furrow series of 
spinelets on the adambulacral plates generally. They are united for a short distance at 
their base by a delicate membranous web, and form a slightly scoop-like marginal fringe. 
On the actinal surface of each plate are seven or eight elongate spinelets in a slightly 
curved lineal series, but sometimes irregular at the inner end of the series, where three 
spinelets may simulate a transverse series. 
1 Memoir of the Echinodermata of the Arctic Sea to the West of Greenland, London, 1881, p. 39. 
