212 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 8 



lar areas darker gray, wreaths of pedicellariae on spines commonly buff, 

 often varying from cream to a rich orange. Regenerating arms somewhat 

 lighter, salmon to orange in color. Actinal surface light gray, tube feet 

 pale yellow. When dried, ground color on abactinal surface of the disk 

 deep walnut brown; color extends on basal half of arm and gradually 

 fades distally to olive buff at tips; network of plates and spines olive-buff 

 with a tinge of brown. Actinal side similar in color but lighter in tone. 

 In alcohol, very pale purplish gray. 



Holotype. — AHF no. 43; 33 paratypes. 



Type locality. — Holotype and 10 paratypes from Station 310-35, 15 

 fms., tangles, Marchena Island, Galapagos, December 3, 1934. Twenty- 

 three additional paratypes as follows: 2 from Station 307-35, 20 fms., 

 tangles, Marchena Island, Galapagos, December 3, 1934; 3 from Station 

 308-35, 3-5 fms., sand, north bay, Marchena Island, Galapagos, Decem- 

 ber 3, 1934; 14 from Station 773-38, 31-50 fms., coralline bottom, off 

 Nuez Island, Cocos Island, Costa Rica, January 13, 1938 ; 3 from Station 

 779-38, 30-50 fms., rock, coral, and coralline, off Nuez Island, Cocos 

 Island, Costa Rica, January 14, 1938; and one from Station 795-38, 35- 

 40 fms., rock and sand, Sulivan Bay, James Island, Galapagos, January 

 21, 1938. 



Remarks. — That this species is fissiparous is well borne out by a study 

 of the 34 specimens examined, in which 11 was the minimum and 17 the 

 maximum number of rays, 13 the average per individual. Specimens with 

 a ray length less than 50 mm. averaged 12.7 rays, while those exceeding 

 50 mm. ray length averaged 13.6 rays. Exclusive of the holotype, 49.3 

 per cent of the rays were young or regenerating rays. Madreporites ranged 

 from 1 to 5 per individual, 3 being the average; 24 per cent of the madre- 

 porites were on young or regenerating portions of disk. In fissiparous re- 

 production a portion of the disk is cast away with the rays. The small 

 madreporites and regenerating rays grow from this section of regenerating 

 disk, which in some specimens is very distinct. There is no definite order 

 or arrangement in the manner the new rays are added to the disk. In gen- 

 eral, 5 or more rays of a first set grow from the regenerating disk ; then 

 at a later period a few scattered rays of a second set appear between the 

 adult rays. In some specimens a third set of rays appears between the re- 

 generating first set just opposite the old adult rays. The average ray 

 length to the disk radius for 20 of the largest specimens is R=9.5 r. 



These are the first Coronasters to be recorded from the eastern tropi- 

 cal Pacific Ocean and increase the number of Pacific species to 4: Coron- 



