HIPPASTERIAS. 77 



Goniaster equestris, Forbes, Brit. Star/. (1840) p. 125. 



Asterias (Goniaster) equestris, Gould, Inv. Massach. (1841) p. 344. 



Astrogoniimi phrvgianuin, M. Tr. Syst. Ast. (1842) p. 52; Sars, 



Norg. JEch. (1861) p. 44 ; Duj. $• Hup. Ech. (1862) p. 390. 

 Goniaster abbensis, Forbes, Ann. § Mag. xi. (1843) p. 260, pi. vii. __ 

 Astrogonium aculeatuni, Barrett, Ann. &; Mag. xx. (1857) p. 47, 



pi. iv. fig. 4. 

 Goniaster phrvolanus, Norman, Ann. fy Mag. xv. (1865) p. 123 



Hodge, Tr. North. # Durh. iv. (1872) p. 135. 

 Hippasterias plana, Pert: Arch. Zool. e.vp. v. (1876) p. 86 ; Dan. &j 



Km: Norske Nordhavs Ast. (1884) p. 59; Sladen, Chatt. Rep. Ast 



(1889) p. 34] ; Scott, Proc. R. Phys. Soc. Ed. 1890-1 (1892) 



P- 82 - 

 Hippasteria pbrygiana, Verr. Rep. Comm. Fish. 1883 (1885) 



p. 542. 



R = 2 r ; or 2 R = 3 r. 



Proportion of rays to radius of disk varies within wide limits ; 

 disk with concave, plane, or convex sides, more or less tumid above. 

 Among known British species it may be at once distinguished by 

 the presence of a vast number of large bivalve sessile pedicellariae. 

 Arms short, triangular, obtuse at their tips. Ambulacral groove 

 narrow ; the spinulation at its sides very variable and irregular ; 

 the most typical arrangement is that of two inner rows of rather 

 large blunt spines and a row or two rows of twice as many smaller 

 spinec. In small specimens the large bivalve pedicellaria? on the 

 ventral surface are pretty regularly surrounded by subequal tuber- 

 cles of some size, but in larger specimens the arrangement of the 

 tubercles is less regular and their similarity in size is less marked. 

 In moderate-sized to large specimens there are from 15 to 20 

 superomarginals and about the same number of inferomarginals. 

 The most ordinary arrangement is the possession of three tubercles 

 bv the most proximal, two by the more distal, and one by the ter- 

 minal superomarginals ; and these may be set, when there is more 

 than one, vertically to one another. On the inferomarginals the 

 number of tubercles is less constant and their disposition less 

 orderly. The upper surface is rougher than the lower owing to the 

 greater projection of the tubercles, among which are numerous 

 bivalve pedicellariae. The madreporite is placed about midway be- 

 tween the centre and the edge of the disk, is distinct, and of fair 

 size. In the largest specimens the disk exhibits a tendency to be- 

 come tumid and the marginals get pressed down to the lower surface. 



Colour in life " pale orange " ( Wingate), in spirit white ; when 

 dried brown to white. 



