NEOJIORPHASTER. ZOROASTER. 81 



2. NEOMORPHASTER. 



Glyptaster, Sladen, Chall. Narr. i. (1885) p. 612 (non Glyptaster, Hall). 

 Neomorphaster, Sladen, Chall. Hep. Ast. (1889) p. 436. 



A Stichasterid in which the primitive calycinal plates remain 

 well marked on the disk, but in which the adambulacral plates do 

 not form projecting angles into the ambulacral grooves. By the 

 former character distinguished from Stichaster, by the latter from 

 Zoroaster ; otherwise it might well be placed in either of these 

 genera. 



1. Neomorphaster eustichns. 



Neomorphaster eustichus, Sladen, Chall. Hep. Ast. (1889) p. 

 pi. lxvi. tigs. 3 & 4, & pi. lxviii. figs. 9 & 10. 



R is equal to rather more than 4 r. 



Disk moderate, pretty deep at the sides, with a circlet of large papulfe 

 close to its margin ; the plates of the disk arranged radially and inter- 

 radially only, save in the centre, where there may be one or more. 

 Along the arms there is a central row of ossicles, and on either side 

 of it there are four rows ; these are all arranged very regularly and 

 the plates are separated by large papuke and ornamented with a spiny 

 granulation. On the adambulacral plates there are ten lines of simple 

 subequal spines. 



Colour in spirit, yellowish white. 



Dredged off S.W. coast of Ireland (51° 1' N., 11° 50' W., 750 

 fms.) ; and off Azores (900 and 1000 fins.). 



3. ZOROASTER. 



Zoroaster, Wyv. Thorns. Depths of the Sea (1873) p. 154; Pen: Nouv. 

 Arch. Mus. vi. (1881) p. 195; id. Aim. Sci. Nat. xix. (1885) art. 8, 

 p. 16; Slad. Chall. Rep. Ast. (1889) p. 416. 



Arms five, more or less rigid, elongated, arched ; covering spines 

 well developed. Ambulacral tubes quadriserial at base of arm, with 

 small sucking-disks ; adambulacral plates hidden in groove. 



In the definition of this genus and in the assignment of it to the 

 family Stichasteridae, it will be seen that I follow Professor Perrier's 

 earlier arrangement rather than that since proposed by Mr. Sladen, 

 for which no definite reasons are conclusively stated. 



* These measui'enients are taken from a series of specimens dredged from 

 the west of Fayal, Azores (St. 73, Voy. ' Challenger '). 



