94 "Mr. A. Alcock on 



cellaria. On the nioutli-platcs the furrow spines become 

 more ])rism-sliaj)otl. 



Actinal interradial areas very large, the intermediate pU\tes 

 extending to about the fourteentli infcro-marginal; thephites, 

 ■which number about 250 in each area, are arranged in about 

 nine chevrons, and decrease cons])icuously in size from 

 actinostomc to margin and from ambuUicium to mid-inter- 

 brachium. 



Madre])orilbrm plate ])entagonal, with fine radial striations, 

 placed not quite a third of the way from the centre to the 

 margin of the disk. 



Tube-feet with a broad sucker. 



Colour in alcohol ivory-white, the ]iapular areas combininc; 

 to form a beautifully synmietrical, dark-coloured, live-petal 

 flower. 



Andaman Sea, 271 fathoms. 



Nymphaster, Sladen. 



27. Nymphaster Jlor if er J sp. n. 



Rays 5. E = 3 r. R = 32 millim. in the 

 type specimen. 



Disk pentagonal, large, very thin and flat ; rays of mode- 

 rate length, very narrow and flat^ ([uadrangular in section ; 

 interbrachial arcs wide. 



Abactinal surface of the disk displaying in the centre and 

 in the radial areas a large and particularly beautiful and con- 

 spicuous rosette of hexagonal paxilliform plates, each inflated 

 petal-shaped segment of the rosette consisting of seven 

 longitudinal rows of plates, of which those in the middle row 

 — coinciding Avith the mid-radial axis — are of jjredomlnant 

 size ; the interradial (interpetaloid) areas are small and 

 triangular and are clothed with small irregularly pentagonal 

 or subcircular ])lates. 



The abactinal surface of the rays, between the plates of the 

 supero-marginal series, is occupied chiefly by a continuation 

 of the large plates, now become rather irregular in shape, of 

 the middle row of the petals, with on each side a discon- 

 tinuous row of platelets. 



The hexagonal plates of the rosette are true paxillaj and 

 consist of a raised tabulum bearing in the centre from one to 

 six (usually two or three) and round the margin from twelve 

 to sixteen flat-toj)ped bacillary granules ; the irregular phites 

 of the interradial (interpetaloid) areas and of the rays arc 

 merely covered with minute granules. 



