l6o VERRILL 



among the ventral and adambulacral spines. The latter bear dense 

 clusters of minor pedicellariae on the outer surface, and near their 

 tips. 



The madreporic plate is large, with numerous fine, forked, radial 

 gyri. It is not surrounded by a special circle of spines. 



Another large specimen (k) from Victoria, British Columbia, 

 differs considerably in the spinulation, especially on the ventral side. 



The radii are 36 mm. and 232 mm. ; ratio, i : 6.45. 



The rays are stout and broad, but unnaturally flattened in drying, 

 so that they taper rather abruptly distally. 



The smaller dorsal spines are numerous, mostly in reticulated 

 lines and in short transverse rows or combs, the transverse lines 

 being most conspicuous proximally and toward the sides of the rays, 

 dorsally; not so evident on the disk. These smaller spines mostly 

 stand in a single row on the narrow carina of the ossicles surround- 

 ing the large papular areas. Part are slender and acute, about i mm. 

 to 1.5 mm. long and 0.25 mm. thick. More than half of them are 

 obtuse or clavate, of about the same length, but from 0.40 mm. to 

 0.60 mm. thick. 



Larger capitate and sulcated spines are scattered among the 

 smaller reticulated spines. They stand on the larger ossicles, and 

 especially along the median radial lines, forming, with many smaller 

 ones, rather irregular radial ranges of spines. On the distal part of 

 the rays the spines become more crowded and the larger ones more 

 numerous, and are then often grouped more or less in clusters. 



The madreporic plate is large, with fine radial gyri, and is sur- 

 rounded by an irregular row of small spines. Minor pedicellariae 

 are thickly scattered over the papular areas and surround all the 

 spines, in small wreaths. 



The superomarginal spines form a pretty regular row, in which 

 the larger, blunt spine on each plate is accompanied by one to three 

 smaller, more acute ones. The ventral spines usually consist of three, 

 often double, rows and a single synactinal row, all crowded pretty 

 closely together, and nearly equal in length, but differing in form. 



Most of the inferomarginal ossicles bear two equal spines and 

 sometimes three, so that there may be from four to seven spines in 

 each transverse range. These spines are mostly rather short, stout, 

 partly blunt, partly tapered, often bent, some of those toward the 

 mouth becoming longer, subacute, and often excurved. They are 

 mostly about i mm. thick and 2 mm. to 3 mm. high. 



