ASTEROIDEA 111 



2-7 r. Ai^parcntly not reaching any large size ; largest size re- 

 corded : 24 mm. R. Colour in life pale yellow, the tube-feet 

 darker yellow. 



Biology and development unknown. 



In British seas this species has been found only in the Faroe 

 Channel (60° 14' N., 6° 17' W., 662 fms., '"' Porcupine "). It is 

 known only from the cold area to Nova Zemlja, Spitzbergen, 

 and East Greenland. Bathymetrical distribution, ca. 180-1150 m. 



V. Family Solasterid.^: 



Disk rather large, arms fairly long, rounded ; five, or more 

 often many arms. Skeleton of dorsal side reticulate ; more rarely 

 larger, imbricating plates, carrying paxillse. No supra-dorsal 

 membrane ; no actino-lateral (fin-like) membrane. A single or 

 double series of larger marginal paxillse, representing the 

 marginal i3lates. Oral interradial plates present. Spines on 

 adambulacral plates in two series at right angles. 



Two genera represented in British (and European) seas. 



Key to the genera of Solasteridce represented in British 

 {and European) seas. 



Arms many (7-15) 1. Solaster Yorheii 



Arms 5 2. Lophaster Verrill 



1. Solaster Forbes. 



Disk large ; rays many, 7-15, or even as many as 17. A 

 single series of larger, marginal paxillae, above which there may 

 be a second series of distinctly smaller paxillse. 



The rather numerous species form two fairly distinct groups, 

 one with short, the other with long j)axill9e. These two groups 

 are often regarded as separate genera, viz. Solaster, in a restricted 

 sense, containing the species with short paxillse, and Crossaster 

 Miiller and Troschel, containing the species with long paxillse. 

 It appears that the two groups differ also in their inner anatomy, 

 Crossaster having an inner septum in each interradius, while this 

 is lacking in Solaster. If this anatomical character proves to 

 hold good for all the species, it would seem necessary to adopt 

 the two genera. For the present it seems hardly sufficiently 

 warranted. 



Three species are known from the British seas, but besides 

 these two more species will probably be found to occur there, 

 viz. Solaster glacialis Danielssen and Koren, and Solaster abyssicola 

 Verrill. The former is a purely Arctic form, known from East 



