ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATERS FISHER. 187 



less prominent inferomarginal spinules, much more compact inferomarginal and 

 actinal intermediate spiniilation, more numerous adamhulacral spinelets, and 

 especially lacks the prominent marginal fascioles of jmsillufi. 



A very j^oung specimen from station 2S60, probably of tiiis race (although in 

 absence of adults from the same station it is not possible to be positive) lias R = 7 

 mm., an arcuate pentagonal form, and a largo naketl area on each of the seven or 

 eight superomarginais of the ray. The athimbuhicral phites have three or four 

 furrow spinelets and the moutii plates an o(hl mouth spine. Tliere are no enlarged 

 inferomarginal spinules as in sniall specimens of j>usiU.us. 



PSEUDARCHASTER PUSILLUS FUher. 



PI. 32, figs. 1-4; pi. 33, fig:?. 1, 2; pi. 57, figa. 4, 4a.- pi. 59, fig. 4. 



Pseudarchaster pimllus Fisher, Bull. Tiur. Fisheries for 1904, vol. 24, June 10, 1905, p. 304. 



Diagnosis. — Rays 5. R = 32 mm.; r=14.5 mm.; R = 2.2 r. Breadth of ray 

 at base, 17.5 mm. A variation with shorter rays: R = 1.8 r. Rays short and 

 broad at base; interbrachial arcs very Avide and rounded; abactinal surface sub- 

 plane to slightly arched. Paxilhe spaced and small or large and more closely 

 placed; very variable; papuliB conspicuous, extending 0.7 to O.S Icngtii of ray; 

 abactinal plates strongly lobed. Marginal plates conspicuous, the inferomarginals 

 with a widely spaced subpapilliform granulation and a median transverse row of 

 four prominent sharp spinules which are reduced to two on outer half of ray. 

 Superomarginais with three to five transverse rows of spaced granules one to tliree 

 enlarged into subtubercular granules on outer end of plate; inferomarginal spine 

 on outer end of plate very prominent in young specimens. Adamhulacral plates 

 angular, with palmate furrow series of four or five terete blunt spinelets, and on 

 actinal surface a semicircle of unecjual "barley-corn" spinelets on border of plate 

 surrounding a similar but enlarged central spinule. Sometimes pectinate pedicel- 

 larise present on furrow between adamhulacral plates, and on some of actinal 

 intermediate plates near mouth plates. Mouth plates with prominent median tooth 

 at inner angle, and an angular marginal series of uneciual spinelets. Actinal inter- 

 radial areas extensive but plates not encroaching far on ray; plates witli "barlev- 

 corn" spinelets and frequently an enlarged spinule. Superambulacral jilates 

 present. 



Description. — The variable shape of this species is noted under '"Variations." 

 PaxilliB usually small and spaced but extremely variable in size; arranged in 

 regular series parallel with median radial, except over center of disk wliere there is 

 no regular arrangement. Paxilla^ also form transverse obliriue series and decrease 

 in size toward marginal plates and center of disk. Paxilh-e of type (and of speci- 

 mens from hard bottom) have three to five robust, but small, clavate or pestle- 

 shaped granules, alternating with or surrounded by a regular series of si.x to ten, 

 or slightly more, slenilerer spinelets or granules. Small lateral paxilla? with onl}- 

 tliree to six spinelets. An extreme variant from type (station 4.367) has large 

 rather closel}' placed paxilliE with a convex crown of upwards to fifteen central low 

 polygonal or roundish granules, surrounded by numerous slender spinelets in a 

 peripheral series. About three transverse rows of paxillse, in this specimen, stand 



