rs 



ASTEROTDEA. 



Distribution. Northern parts of Atlantic, on both sides : White 

 Sea, To 150 fms. 



a. Coast of Northumberland. R. Howse, Esq. 



b. Coast of Northumberland. 



c. North of England. Dr. G. Johnston. 



d. North of England. Dr. G. Johnston. 



(4-rayed form.) 



e. St. Abb's Head, Berwickshire. Prof. E. Forbes. 

 /, g. St. Andrews. Prof. MTntosh.' 

 h, i, Montrose, July 1889. W. Duncan, Esq. 



J. Aberdeen. L. G. Esson, Esq. 



k, I. Coast of Ross-shire. Dr. Sutherland. 



to, n. English coast. Dr. Bowerbank. 



MIMASTERIN^E (see p. 21). 



MIMASTER. 



Mimaster, Sladen, Proc. Roy. Soc. Ed. xi. (1882) p. 702 ; id. Trans. Roy 

 Soc. Ed. xxx. (1883) p. 579; id. Chall. Rep. Ast. (1889) p. 331. 



"With the characters of the subfamily (see p. 21). 



1. Mimaster tizardi. 



Mimaster tizardi, Sladen, Proc. R. Soc. Edinb. xi. (1882) p. 702 • id 

 Trans. R. Soc. Edinb. xxx. (1883) p. 580, pi. xxxiv. ; id, Chall. 

 Rep. Ast. (1889) p. 333. 



R = 2-2 r. 



A large species, with short triangular rays, swollen disk, thin 

 margins formed by the marginal plates alone. Paxilla? compact and 

 subequal. Rather less than forty marginal plates in each series, the 

 lower larger than the upper. Adambulacral armature formed of 

 delicate spines varying in number and arrangement. Madreporite 

 obscure. 



Colour, in spirit, yellowish or light brown. 



a. Faeroe Channel, 555 fms. ' Knight Errant ' Exp. (St. 4). 



b, c haeroe Channel, 516 fms. < Triton ' Exp. (St. 10). 



d. baeroe Channel, 555 fms. < Triton ' Exp. (St. 11). 



Not known from any other locality. 



GYMNASTERIID./E {see p. 21). 



Key to the Genera of Gymnasteriidae. 



A. No spines on dorsal plates 1. Porania, p. 79. 



H. Spines or spinelets on dorsal plates. 

 a. Superomarginals obscure. 



_i. With no broad marginal fringe . . 2. Rhegaster, p. 80. 



"• Wltn a broad marginal fringe 3. Cheilaster, p. 81. 



p. Superomarginals distinct 4. Lasiaster, p. 81. 



