322 BULLETIN 76, UNITED STATES NATIONAL MUSEUM. 



examples. The mouth j)lates are decidedly narrower in specimens with twelve 

 rays than in those with nine (station 3607). 



Madreporic body variable in size, exposed and situated at inner end of an 

 interradial sulcus. Two or three large paxillse stand near it. 



Color in life, of a CaUfornian specimen: Abactinal surface, dull orange or saturn 

 red ; dull hght yellow below. 



Variations. — All the specimens from station 3607 have nine rays, which are 

 broader than in the type. There seem to be no important constant differences 

 in the ornamentation however. Specimens with ten and eleven rays are present 

 in the collection but nine and twelve are the prevalent numbers. Size has appar- 

 ently nothing to do with the number of Ta.js. Variations in the number of furrow 

 spines and subambulacral spines have been alluded to in the description. The 

 increased number of furrow spmes can not be correlated with other constant differ- 

 ences. Certain specimens, especially those from station 3607, have curious shts in the 

 web at the base of the furrow spines of mouth and adambulacral plates. Examples 

 with fewer rays have the paxillse more widely spaced than those with eleven or 

 twelve rays. Owing to the broader mouth angles in examples with nine and 

 ten rays, the mouth plates are broader than in specimens with twelve rays. 



Specimens from Cahfornia to Queen Charlotte Islands have a different appear- 

 ance from the more northern examples and perhaps deserve to be separated as a 

 race of tyjiical iorealis. The abactmal paxillse are lower, both the spinelets and 

 pedicels being shorter, and the spinelets blunter, the rays are often slender (ten 

 to twelve in number), the marginal paxillse have rather fewer spines and the 

 subambulacral spines are only two or three and less heavily covered with 

 membrane. Oral spines eleven to tliirteen, the suborals are one or two, or 

 absent. The differences are most pronounced in the specimen from station 4415 

 between Santa Catalina and Santa Barbara Islands, 638 fathoms. 



I have examined a twelve-rayed sjjecimen from station 5050 off" the east coast 

 of Honshu, Japan (hit. 38° 11' 30"), 266 fathoms. The rays are shorter than 

 in typical examples (R = 52 mm., r = 22 mm., R = 2.36 r). A nearly equal-sized 

 specimen from Monterey Bay has R = 2.7 r. There is a thirteen-rayed specimen 

 from station 3489, Bering Sea, which has H = 2.1 r. The length of ray is therefore 

 variable even in typical examples. The most important difference is the small 

 number of three furrow spinelets throughout most of the furrow. There are nine 

 oral and one to three suboral spines. The paxiUae are fairly typical with two 

 to four or five tapering spinelets. The bare interradial streaks or lines are weU 

 marked. 



Type.— Ca,t. No. 21933, U.S.N.M. 



Type-locality. — Albatross station 2858, east of Kadiak Island, Alaska, in 230 

 fathoms, on blue mud and gravel. 



Distribution. — From off San Diego, California, to Bering Sea, thence to Honshu, 

 Japan, 225 to 1,044 fathoms. 



