. REPORT ON. THE ASTEROIDEA. XXXVil 



Subfamily 2. Korethrasterin.e, Sladen, 1888. 



Solasteridse with the armature of the adambulacral plates forming with that of the 

 actinal intermediate or infero-marginal plates a single transverse series. 



Genus 1. Korethraster, Wyville Thomson. 

 Genus 2. Peribolaster, Sladen. 



For a Synopsis of the Subfamilies and Genera included in the Family Solasteridse, see 



p. 442. 



SoLASTERiDiE incertee sedis. 



Genus Ctenaster, Perrier. 

 Genus Racliaster, Perrier. 



I have followed M. Perrier in placing these two genera in the Solasteridse ; I am 

 unable to speak of either of the forms from personal knowledge. The descriptions and 

 figures are insufficient. 



Family V. Pterasterid.e, Perrier, 1875. 



Cryptozonate Asterids with the abactinal skeleton formed of cruciform or stellate plate3, 

 bearing paxilliform groups of spinelets. With a nidamental cavity formed by a supra- 

 dorsal canopy, opening centrally by a valvular structure. In some forms the supradorsal 

 membrane may be partially or wholly aborted. Segmental apertures and papilla? usually 

 present. Actino-lateral spines when present forming a fine web, or merged in the actinal 

 floor. No actinal intermediate plates. No interbrachial septa. No pedicellarise. 



Subfamily 1. Pterasterin^e, Sladen, 1888. 



Pterasteridss furnished with a supradorsal membrane. With actino-lateral spines. 

 With segmental apertures. Form disco-pentagonal, rays slightly produced. Abactinal 

 spinelets long, forming highly developed pedicellated paxillse. 



Genus 1. Pteraster, Muller and Troschel. 



Genus 2. Retaster, Perrier. 



Genus 3. Marsipaster, Sladen. 



Genus 4. Calypt raster, Sladen. 



Genus 5. Hymenaster, Wyville Thomson. 



Genus G. Benthaster, Sladen. 



• Genus 7. Myxaster, Perrier. 



Genus 8. Cryptaster, Perrier. 



