ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATERS FISHER. 93 



covered with robust squamiform granules, which increase in size toward the aboral 

 edge of plate, the squamules being pointed outward and aborally. On the 

 outer part of the aboral edge (on margin of ray) are a number (six to twelve) of 

 pointed squamiform or tubercular spines directed distad, an<l forming a fringe 

 overhanging the proximal border of adjacent i)late. They are stoutest and bluntest 

 on the very edge of ray and are graduated in size actinally, sometimes extending 

 nearly to inner edge of plate on the distal portion of ray. Frequently they form 

 two irregular series. The squamules of plate are graduated in size up to these. 

 In interbrachial angle where the plates are much shorter the spines form a median 

 row. On the abactinal end of the plate arc small granuliform spinelets similar to 

 those on adjacent portion of superomarginal; and on the edge of the fasciolar 

 grooves are slender blunt spinelets. In general, the covering of the inferomarginals 

 is much more compact, heavy, and squamiform than is that of eximivs. The 

 difference is very striking ou comparison of the two forms. 



Adambulacral plates about as long as broad, with a rounded furrow margin, and 

 separated by fairly wide sutures. Armature consists of (1) a furrow series of four, 

 five, or six robust round-tipped spines, which are mucli longer than plate, and are 

 graduated in size toward either end of series. These spines, at least the four central, 

 are usually more or less flattened with the broad side to furrow, and the tip is 

 usually expanded. (The same spmes in eximiiis are strongly compressed, tapering, 

 and with edge to furrow.) Commonly, the spine, at either one end of the series or 

 the other, or both, is tapering, much smaller (two-thirds to three-fourths length of 

 large spines), and stands back from the margui, slightly out of line. Wlien there 

 is a smaller spine at both ends of series, there are usually six spines in all. Near 

 extremity of ray there maj- be but tliree spinelets in furrow series. (2) On actinal 

 surface of plate are six to nine rather small-spaced, tapering, blunt spinelets, which 

 form two irregular series, or are without definite order. Those nearest margm are 

 longest. The lateral members of the furrow series frequently stand back far 

 enough to be in line with the actinal spinelets. The latter, however, are smaller and 

 distinctly tapered. The first j)late is not much modified, and has six or seven fur- 

 row spines and a variable number of actinal spinelets. The outer edge of plate 

 abuts against the side of the mouth plate. It is not so compressed as in eximius. 



Mouth plates prominent, broader at inner than at outer end, with a curved 

 margin at mouth of furrow. Furrow spines in a curved series, eight or nme in 

 number, increasing in size toward the inner end of plate; all are heavj-, usually 

 with thick tips, the inner ones being compressed in varying degrees. The spuies 

 are not so thin and knife-like as in eximius. A series of very small spinelets borders 

 the edge next to first adambulacral, and another, consisting of short but thick 

 and blunt spines, follows the median suture border. These lack regularity in size 

 and shape, but are often quadrate in section, and much thicker than the same 

 spinelets in eximius. A few intermediate in position between the two series may 

 be present. 



Actinal intermediate areas considerably smaller than in eximi'us, especially on 

 ray. A single series (that next to furrow plates) extends 0.8 length' of ray meas- 

 ured along its side; second series, 0.5; third series, 0.23; fourth series, less than 



