Boone, Echinodermata, Cruises of "Eagle" and "Ara," 1921-28 95 



with three or more papulae in each group. The plates of the dorsal 

 surface each bear short, blunt spines, 1 to 2 mm. high, usually singly, 

 but sometimes two or three together. Each spine is finely spinose at 

 the apex, and is encircled at the base with a ring of pedicellariae, 

 each of which is very blunt. The other pedicellariae scattered over 

 the dorsal surface are large and quite acute. There is a very well 

 defined lateral series of spines along the side of each ray below which 

 there is a longitudinally extended area devoid of spines but with 

 numerous pedicellariae. This lateral series varies in position, some- 

 times being quite near the abactinal surface, on the other specimens 

 scarcely visible from above. It consists of plates bearing two spines 

 side by side, so that there is apparently a single line of spines. In 

 older specimens there is frequently a third spine below the distal one 

 of each pair, and a fourth spine above, or beside the proximal one. 

 Farther down on the actinal surface of the ray occurs another series 

 of spines which are largest and most conspicuous. These are 2 to 4 

 mm. long, distinctly blunt-tipped ; they occur in series of three spines 

 forming an oblique row on each plate, with the most distal spine 

 nearest the ambulacral furrow. Pedicellariae are numerous with these 

 spines but seldom encircle them. The adambulacral plates are closely 

 packed together, being much more numerous in this species than in 

 any of its near relatives of the East American coast. Each adam- 

 bulacral plate has usually two spines, which are somewhat compressed, 

 with the apex, pointed, clavate or squarely cut; each spine with one 

 to five long, very slender, acute pedicellariae on the adambulacral 

 plates within the furrow. The oral spines are long, slender, quite 

 similar to that of the adambulacral spines and affording no specific 

 characters. The tube-feet are in four longitudinal rows, closely 

 crowded together. 



References : Asterius rubens Gould, Kept. Invert. Mass., p. 345, 1841. 



Aster acanthion rubens Desor, Proc. Boston Soc. Nat. Hist., vol. Ill, 



p. 67, 1848. — Stimpson, Smithson. Contrib. Knowl., vol. 6, p. 14, 



1853. 

 Asteracanthion violaceus Stimpson, op. cit., p. 14, 1853. 

 Asteracanthion pallidus A. Agassiz, Proc. Amer. Acad. Sci., p. 106, 



1863, no description. 

 Asterias vulgaris Packard, no description, Canadian Naturalist, vol. 



VIII, p. 405, 1863.— Verrill, Proc. Boston Soc. Nat, Hist., vol. 10, 



