236 



BULLETIN "6, UNITED STATES NATIONAL MUSEUM, 



ical, or cylindrical granules, immersed like the rest in thin membrane. On some 

 specimens these arc almost wanting; on others they are prominent and compressed, 

 sometimes subtubcrcular and thimble-shaped. 



Mouth plates prominent actinally; furrow spines five or six, considerably com- 

 pressed, the inner spines the larger and heavier; on actinal surface an incomplete 

 series of three spines, parallel with the furrow, usually one near the inner angle and 

 one or two near the outer end of the furrow series; remainder of surface covered 

 with rugose granules, often curiously compressed or pinched, with denticulate edges, 

 these formmg a row on the median suture margin and another adjacent to first 

 adambulacral plate. 



Madreporic body variable in size, ranging m two large equal-sized specimens 

 from 4.5 to 8 mm. in diameter; situated nearly midway between center ancl margin 

 of disk; striations ratliating and often interrupted. 



Color in life coral red. A large aberrant specimen from station 4530 was col- 

 ored as follows: Abactmal surface salmon orange; the marginal plates and actinal 

 surface yellowish buff. 



Anatomical notes. — The inner organization is very similar to that of //. spinosa. 

 The intestinal coecum is, however, much smaller, consistmg of short-branched radi- 

 atuig, irregular, and unequal tubes. There are five Polian vesicles. 



Type.— Cat. No. 22339, U.S.N.M. 



Type-locality. — Albatross station 4429, off Santa Cruz Islantl, California, 680 

 fathoms, green mud, black pebbles, shells. 



Distribution. — Southern California to Washington, 266 to 847 fathoms. 



Specimens examined. — Twenty from the following stations: 



Specimens of Hippastcria califarnica examined. 



Nature of bottom. 



yellow mud 



do....^ 



gray sand, gravel, broken shells 



green mud 



do ,. 



clay 



fine gray sand 



black sand, mud 



green mud 



fine gray sand 



gray sand 



black mud 



green mud 



black sand, pebbles 



soft gray mud 



U. S. Nat. Mus. 



Do. 

 Do. 

 Do. 

 Do. 

 Do. 

 Do. 

 Do. 

 AlbatToes, 1904, 

 Do. 

 Do. 

 Do. 

 Do. 



a Probably Incorrectly labeled. 



Remarlcs. — This species is remarkable for the small marginal plates and for the 

 shape of the pedicellariae of the actinal surface. The granules and adambulacral 

 annature are also diflerent from those of phrygiana and spinosa. The abactmal 

 skeleton is weaker than that of phrygiana, but does not present the fenestrated 

 apjieararfce of heathi. 



