569 



larger papular areas which frequently extend from the midradial line 

 to the superomarginal plates without a break ; meshes of actinal skeleton 

 very wide. Spines slender, long and sharp; adambulacral spines also 

 slender, tapering, and pointed, and without grooves. No calcareous 

 grains and tiny plates in the integument of papular areas. 



Off Santa Catalina Island, Cal., 334 — 600 fathoms. Bottom, rocks, 

 shells, fine gray sand. 



The two California forms may be contrasted as follows: 



a. Adambulacral spines with a groove; rays rigid and 



skeleton stout; adradial row of intermediate ossicles 



always present inflata. 



aa. Adambulacral spines tapering, without a groove, rays 

 weak and flexible; adradial series of intermediate ossi- 

 cles sometimes absent flexilis. 



Henricia Gray. 

 In the following key, most but not all the species of North Pacific 

 Henricia are included in order to bring out the differences of the new 

 forms. 



a. One furrow spinelet, except sometimes on the distal 

 portion of ray, where 2 may be present on the furrow 

 face of the adambulacrals. 



b. All the pseudopaxillae or groups of spinelets small, 

 rather close-set, the abactinal skeleton not forming an 

 open meshwork; pseudopaxillae with comparatively 

 few (1 — 15) short spinelets; papulae few (1 to 3, less 

 often 4 or 5) to an area. Rays moderately long and 

 slender; marginal plates typically inconspicuous , and 



not normally forming regular series. . . sanguinolenta (Müller), 

 bb. Abactinal pseudopaxillae moderately to very large, 

 close-set, with numerous small delicate, sometimes 

 granuliform spinelets; papular areas small, typically 

 smaller than the pseudopaxillae; marginal and actinal 

 intermediate plates forming 3 very regular, conspicuous, 

 juxtaposed series. 



c. Abactinal pseudopaxillae typically with small granuli- 



form or davate spinelets; adambulacral spinelets few 

 in about 2 transverse series. Typically 1 spinelet in 

 furrow except at very tip of ray where 2 may be present. 



d. Papular areas smaller than adjacent pseudopaxillae 

 which have usually more than 20 spinelets; marginal 

 plates squarish, large, not much wider than long, not 



