REPORT ON THE ASTEROIDEA, XXXVI1 
Subfamily 2. KorerHrasTEkrIy®, 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 Solasteride, see 
p- 442. 
SoLaSTERIDA incerta sedis. 
Genus Ctenaster, Perrier. 
Genus Radiaster, Perrier. 
I have followed M. Perrier in placing these two genera in the Solasteridze ; I am 
unable to speak of either of the forms from personal knowledge. The descriptions and 
figures are insufficient. 
Family V. PTERASTERIDA, Perrier, 1875. 
Cryptozonate Asterids with the abactinal skeleton formed of cruciform or stellate plates, 
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 papille 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 pedicellarie. 
Subfamily 1. PrerasTertn#, Sladen, 1888. 
Pterasteridee 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 paxille. 
Genus 1. Pteraster, Miiller and Troschel. 
Genus 2. Retaster, Perrier. 
Genus 3. Marsipaster, Sladen. 
Genus 4. Calyptraster, Sladen. 
Genus 5. Hymenaster, Wyville Thomson. 
Genus 6. Benthaster, Sladen. 
Genus 7. Myzaster, Perrier. 
Genus 8. Cryptaster, Perrier. 
