156 BULLETIN 76, UNITED STATES NATIONAL MUSEUM 



it is not always possible to determine the number of pairs of adambulacrals involved — 

 usually 10 to 15. (PI. 79, fig. 3.) The spines increase in length and robustness as 

 the oral plates are approached. (PI. 79, fig. 2.) 



Mouth plates small, with one or two actinostomial and one longer suboral spine. 

 (PI. 79, figs. 2 and 3.) In live and fresh alcoholic specimens the plates are obscured 

 by pompons of tiny pedicellariae (pi. 77, fig. 1) similar to those occurring on the 

 adambulacrals. 



The crossed pedicellariae vary greatly in size according to age of the specimen. 

 In large specimens (R 200 to 300 mm.) the abactinal are commonly 0.35 to 0.45 

 mm. in length (Unalaska, Vancouver Island, Monterey; pi. 78, figs. 1-3). 



The large, characteristic, ovoid straight pedicellariae are found on the abactinal 

 surface, marginal plates, and proximal adambulacral, and mouth plates. They 

 reach a length of 1.75 mm., or occasionally slightly more in giant specimens. Such 

 as are shown in Plate 78, Figures 4 and 5, may be found on the same specimen. The 

 small straight pedicellariae, commonly 0.15 to 0.2 mm. long, have been noted in the 

 foregoing description. 



Madreporic body single, large (upwards of 12 mm. in diameter), situated a little 

 adcentrally to the middle of r; striae very numerous, fine, radiating. 



Color in life ranging from yellow and reddish through yellowish brown to violet 

 brown, purplish, and slaty violet. The color of a specimen varies according to the 

 inflation of the papulae and expansion of the pompons of pedicellariae which may 

 almost entirely obscure the underlying skin color. 



At Nanaimo large specimens may be flame scarlet, the clusters of pedicellariae 

 yellow; or mottled rufous and dragon's blood red, the pedicellariae hazel; actinal 

 surface pale yellow. Three rather prevalent color phases are furry gray, salmon 

 color, and purplish or slaty purple. 



In the Monterey region the yellow-red phase is uncommon, brown and violet 

 predominating. A rather common mode: Papulae and pompons of pedicellariae 

 mottled slaty violet and dark brown (chocolate, Vandyke brown, seal brown), the 

 disk clear dark brown and the large pedicellariae whitish. The actual skin under- 

 neath, showing only in spots when the animal is at rest, orange red to brownish red 

 (dragon's blood, Nopal red, Brazil red). Variations are decidedly purplish especially 

 on outer part of rays and actinally (inferomarginals). Furrow pale yellow; tube- 

 feet orange near end, the sucker pale straw. 



At Port Renfrew, Vancouver Island, where the species is large and common, 

 Dr. J. C. Brown found the color varying from rich orange, or even light lemon yel- 

 low, to dark lilac or brown above, with orange yellow on the actinal surface. A 

 specimen with 10 rays had a yellowish brown background, the middle of disk and 10 

 radiating lines to end of rays blue-black; ambulacral areas slate blue. The yellow 

 color of the background was sometimes almost a buff color, while again it was almost 

 pure coral red but the blue-black banding was not variable in specimens so marked. 

 An 18-rayed specimen was claret color where the papulae were distended, but showed 

 deep orange as they contracted. 



Anatomical notes. — The abactinal skeleton, as already indicated, is obsolescent, 

 the spines and pedicellariae outweighing the plates themselves. The absorbed plates 

 of old specimens may go to form the skeleton of newly added rays. In the very 

 tough dorsal integument of old specimens (often fairly leathery where well preser- 



