ASTEROIDEA 87 



1. Pseudarchaster Parelii (Diiben and Koren). (Fig. 49.) 



(Syn. Astropeden, Archaster, Plutonaster, Tethyaster, 

 Astrogonium Parelii (Diib. and Kor).) 



Upper marginal plates covered with close-set, flat-topped, 

 hexagonal granules, those along the sutures somewhat smaller. 

 Lower marginals with some appressed spines along the mid- line. 

 Oral interradial plates with small spines and a few larger ones 

 among them. Adambulacral plates with 5-6 furrow spines, and 

 outside these one or two somewhat enlarged spines surrounded 

 by some smaller ones not arranged in regular series. Generally 

 3-6 pectinate pedicellarise along the adambulacrals ; no bivalve 



Fig. 49. — Pseudarchaster Parelii, dorsal and oral side. Nat. size (small 

 specimen), (From Danjnark's Fauna.) 



pedicellarise. R = ca. 3 r. Colour in life red-brown or red on 

 the upper side, lighter coloured on the oral side. 



Grows to a very considerable size, to nearly 20 cm. R. It 

 would seem to take at least four years in reaching adult size. It 

 appears to feed, partly at least, on detritus, which is carried to 

 the mouth by ciliary currents. Development unknown. 



Var. longobrachialis Dan. and Koren is distinguished by 

 relatively somewhat longer and more slender rays, but especially 

 by the dorsal marginal plates being narrower, encroaching 

 less on the dorsal surface than in the type ; in accordance here- 

 with there is more room for the paxillse, which are somewhat 

 larger in the variety than in the typical form. 



In British seas this species has been taken off N. and W. Ireland 

 (" Porcupine ", " Helga "), in ca. 500-1100 m., but only in small 



