ASTEEOIDEA OF NORTH PACIFIC AND ADJACENT WATERS FISHER. 145 



may touch by the lobes or may be entirely separated. Beyond papular area plates 

 lose the lobes, are irrefjular to quatlrate elhpticul hi form, and on tlie outer part of 

 ray are quite widely spaced. Papuhe numerous, one to a pore, and distributed all 

 over disk (except narrow interradial line), and basal part of ray, but from fourth to 

 fifth superomarghial to far along ray (var\'uig from eighth or ninth to twentieth 

 superomarginal) the papuloc are confined to either side of the medioradial area. 

 Naturally the papuhr dwuidle as they recede from disk. Thus the extent of the 

 papular area on rays is variable. The papulie extend farther along ray than in 

 any other species of the genus. 



Marginal plates thin, confined to side wall of ray, elongate elliptical in form, 

 the inferior margin of the superomarginal bemg slightly oblique to long a.xis of ray. 

 The plates of the two series are nearly opposite. Superomarginals fift3'-four, each 

 bearmg on a prominence of the center a long slender tapering spine, that of 

 third and fourth plate being longest (8 nun.) except for the odd inteiTadial spine. 

 Two or three capillary spinelets stand on the adoral half of the plate and one or 

 two near the spine. Inferomarginals each with usuall\- two spmes in a vertical 

 row, the lower, half or two-thirds the length of the upjier; the latter about the 

 length of superomarginal spines. A few scattered capillary spinelets stand on the 

 general surface. Dorsal interradial marginal bears a 10 to 12 mm. spine and 

 several spinelets. A large and two small specimens from station 2919 have no Qjild 

 plate in either series in one interradius. The odd inferomarginal is armed with one 

 or two shorter spines. Between the odd mferomarginal and the first i)aired plate, 

 between the first and second, and sometimes the second and third or third and 

 fourth also, is a prominent jjedicellaria with six to ten tapermg spines in each comb. 

 The longest of these spines equals one-third or slightly more of the length of the comb. 

 The apparatus does not usuall}^ occupy the whole height of the plate. One or 

 two additional pedicellariffi occasionall}- occur in the neighborhood of the seventh 

 to tenth plates, but beyond that inferomarginal pedicellaria? are absent. 



Adambulacral plates with a semicircular prominence into furrow. Armature 

 consists of (1) a furrow comb of four or five slightly curved, slender, blunt spinelets, 

 three of which are about equal, the extra ones (laterals) being shorter. One speci- 

 men (station 2919) has regularly six or seven furrow spinelets. There is a wide 

 interval between successive combs. (2) On actinal surface of plate are two slender 

 slightly tapering blunt spmules in a transverse series, sometimes the inner, some- 

 times the outer being the longer, the longest equahng one and one-half to two 

 plates in length. 



Mouth plates large, convex actinally. Armature (1) a furrow series of four 

 or five spines wliich increase rapidly in size toward the inner angle, where the 

 mnermost of each plate form two promment teeth, much heavier than the others. 

 (2) On the actinal surface is a linear series of four or five rather long, slender, 

 blunt spines, decreasing in length toward outer end of plate; the inner two stand 

 in a series parallel with furrow, the rest parallel to suture. 



Actinal interratlial areas very small. In the ty])e the second adambulacral 

 plate is in contact with the first paired inferomarginal: this is, however, extreme. 

 The two other large specimens have either the fourth or fifth aiiambulacral touching 

 57444°— Bull. 76—11 10 



