ASTEROIDEA OF NORTH PACIFIC AND .VDJ AC KN T WATERd — FISUEB. 209 



times lack peclicellana>, but usually most of tho plates have one or even two which 

 are slightly larger than the superomarginal ones. 



ActinalinU rmidiate j>latcs. — A characteristic of this species is the very crowded 

 polygonal, flat-topped, smooth actinal intermediate granules. They are not at all 

 globular, and this character seems fairly constant. It is well marked in the Wash- 

 ington specimens and serves admirably in connection with other features to separate 

 japonicus from leptoceramus. Tho latter species has spaced hemispherical granules. 



The small bivalved pedicellariae vary considerably in numbers. They may 

 be restricted to the angle adjacent to mouth plates, or scattered part way or all 

 along the row of plates adjacent to adambulacrals. Many specimens, but not a 

 majority, have them also sjjaringly elsewhere on tho intermediate areas (Misaki, 

 Washington, Bering Sea.) 



Adamhulacral plates. — In proportions the plates vary from being as wide as 

 long to wider than long. The outer edge is frecpiently oblique or obtusely angular. 

 The furrow spinelets are prismatic or subquadrate in section, blunt, usually but 

 not always with a slightly curved, oblique, base-line. The Washington examples 

 have pro.ximalh^ four or five, rarelj' sLx, furrow spinelets, distally three to five; the 

 Misaki specimen pro.ximally six or seven, distalh- sLx spinelets, and the base line is 

 more evidently oblique. Large Alaskan examples have proximally five or six 

 spinelets, distally four or five. Young Alaskan specimens (R = 30 mm.) have four 

 or five furrow spinelets throughout. The ^lisaki specimen has rather shorter 

 spinelets than the Alaskan and Washington examples. The first series of actinal 

 granules varies from three to five. Far along the furrow one of these granules is 

 enlarged into a blunt tubercle. The bare space between the furrow spinelets and 

 first scries of granules is variable in width, wider in the Japanese specimen than in 

 the Alaskan or Washington examples. The number of granules exclusive of the 

 first series varies from about tw-elve to twenty-two. The small number occura 

 when there is a pedicellaria on the plate. In specimen A, before cited, very few 

 of the adambulacrals have pedicclhiria'. In the Misaki example nearly all have 

 one. Nearly as great a range of difference is present in the Washington examples, 

 and in Bering Sea specimens, as, for example, station 3608. 



Young. — The young bear a great resemblance to G. granulans (Retz.). In 

 this species, however, the superomarginals arc longer than wide, whereas all the 

 young japonicus have them WMder tiian long. Granulans lacks pedicellariiB alto- 

 gether, the abuctinal tabuhe are flat-topped with large marginal granules, and the 

 actinal intermediate granules are roundish and not crowded. The adamhulacral 

 armature is coarser and the spinelets and granules fewer. In young japonicus 

 the papulae are restricted to broadly ovate areas on the radii, the tabula are lower 

 with fewer granules, and no abactinal pedicellariaj or only few. The marginal 

 plates are sometimes relatively thicker than in the adult. 



Type. — In the British Museum. 



Type-localitij. — Challenger station 'I'.Vl, south <>f "iOkohumu, Ja])an, 3-)."i f.uh- 

 oms, green mud. 



Distribution. — Japan (Misaki, and south of Yokuhama) tu southern Bering 

 Sea, thence south along the American coast t<> Oregon. 

 57444°— Run. ?«— 11 14 



