76 Mr. A. Alcock on 



2. Fararcliaster Iluddlestonu, sp. n. 



Eays 5. R = ll r. R = about 170 millim. in the 

 type specimen. 



Disk very small ; rays depressed, very long, tapering. 



Abactinal surface covered with small, rather distant, 

 unequal-sized nodular plates, each of which bears a single 

 erect acute spine or spinelet, the spines on the disk being 

 very stout and measuring in the type specimen 5 to 8 

 millim. in length, while the spinelets on the rays are small 

 and slender and decrease in length from about 2 millim. near 

 the base to less than a millim. at the periphery of the ray. 



Supero- marginal plates more than 60, entirely lateral and 

 slightly oblique in position, elongate, oval, tumid ; each with 

 a central tubercle bearing a stout acute spine with a basal 

 circlet of spinelets, one of which is sometimes considerably 

 enlarged, especially in the interbrachial region ; the odd 

 interbrachial plate is in the form of a salient eminence, upon 

 which stands a spike of preeminent size with a basal circlet 

 of spinelets larger than those on the other plates. 



Infero-marginal plates alternate with the supero-marginals 

 and very oblique, elongate, pyriform, tumid ; each bears 

 usually three stout sharp spines in an oblique series, the most 

 abactinal being the largest and often having at its base a pair 

 of spinelets ; in the interbrachial arc the spines, especially 

 those of the odd plate, are a good deal aborted. The intervals 

 between the infero-marginal plates throughout the ray are 

 occupied each by a large multivalve or pectinate pedicellaria. 



Adambulacral plates large, broad, tumid, each with a 

 furrow-series of six to eight compressed obtuse spinelets in a 

 semicircular comb, and with three spinelets obliquely placed 

 on its actinal surface, the two of these nearest the furrow 

 being of conspicuous size. 



Mouth-plates large, each with a furrow-series of six or 

 seven spinelets, increasing in size from periphery to centre, 

 and with a suture-series of three much larger spinelets. 



Actinal interradial areas very small, not extending beyond 

 the second or third marginal plate ; the intervals between the 

 plates occupied by large multivalve (pectinate) pedicellariae, 

 but the plates are otherwise quite unarmed usually. 



Anus subcentral, Madreporiform plate large, subcircular, 

 flat, with fine radial striations. 



Ambulacral furrow wide; tube-feet very large, with a 

 small sucker at point. 



Papulae confined to rudely stelliform areas at tlie very base 



