ASTEROIDEA 143 



any food. (In a nearly related species, Leptasterias groenlandica 

 (Steenstrup) , the eggs are taken into the stomach itself and 

 undergo their whole development there.) 



In British seas this species (generally recorded under the name 

 Aster ias his p Ida) is known from S.W. Ireland (Dingle Bay — new 

 record), the Irish Sea, the Clyde, Rona, and from the Shetland 

 Islands to Dogger Bank. Very probably it is common all round 

 the coasts, excepting, perhaps, the South coasts. It is not known 

 to the south of the British seas ; towards the north it occurs 

 on the Scandinavian coasts, to Spitzbergen and the Siberian Sea ; 

 further at Iceland, Greenland, and the N. American coast, down 

 to 44° N. Probably it occurs also in the Bering Sea, being in 

 that case doubtless circumpolar. Its bathymetrical distribution 

 is from the tide limit down to ca. 800 m. 



3. Marthasterias Jullien. 



Rays 5, rather long ; dorsal skeleton of arms fairly regular, 

 especially the median series of ossicles. Sj^ines rather strong, 

 surrounded by a conspicuous wreath of pedicellariae. No ventro- 

 lateral spines. Adambulacral spines in a very regular single series 

 (" monacanthid "), not carrjdng pedicellariae. 



Only one sjDecies in British and European seas. 



1. Marthasterias glacialis (LinnsQus). (Fig. 82.) 



(Syn. Asterias, Uraster, Aster acanthion^ Stolasterias glacialis 

 (Linn.) ; Asterias madeirensis Stimpson ; Asterias spinosa 

 Pennant ; Marthasterias foliacea Jullien.) 



Disk small, fairly weU defined against the long, narrow, gently 

 tapering arms. Spines along the mid-dorsal line of arms and on 

 the marginals very conspicuous and forming regular longitudinal 

 series (upper marginals with one, lower marginals with two 

 spines), giving the arms (especially on dried specimens) a rather 

 angular appearance. Between the mid- dorsal and the marginal 

 spines another more or less regular series of spines may be found ; 

 but these spines may be lacking completely. The furrow spines 

 rather slender. The crossed pedicellariae very numerous, forming 

 a thick cushion at the base of each of the larger dorsal and 

 marginal spines ; straight pedicellariae scattered on the dorsal 

 side ; also on the adambulacrals, within the furrow, but not on 

 the furrow spines. R = ca. 5-9 r, the length of arms being 

 relatively much larger in large than in small specimens. Reaches 



