7S ^Ir. A. Alcock on 



I^accadive Sea, 1200 fathoius, coral and Gluhlgerina- 

 ooze. 



PONTASTER, Sladen. 



4. Pontaster vnmi'cuSj Sladen. 



l\iiiastfr viimmis, Sladen, ' Cb.illengor ' xVsteroidea, p. 48, pi. vi. figs. 1 

 and '2, pi. vii. figs. 5 and 6. 



Laccadive Sea, 1000 fathoms, olive mud. 



5. Pontaster cribellum, .=:p. ii. 



Kays 5. E = 5r. I\ = 4o nilllim. in the 

 type specimen. 



Very closely related to P. suhtuherculatus, Sladen, from the 

 South Pacific Ocean. 



!No pcdiccllarife of any kind present. 



Di.'ik of moderate size ; rays rather short. 



Ahaetinal surface covered with small paxillre formed of 

 from six to twelve uniformly minute spiniform granules, three 

 or four round tlie madreporiform body, and one in each inter- 

 radius having about twenty granules. 



Jilarginal plates uniformly covered with similar granules. 



Supero-marginal plates about 21, broad, tumid, almost 

 entirely abactinal in position, articulating rath.er obliquely 

 with one another ; each with a central eminence supporting 

 a .'^iugle stout sharp spine. 



Inlero-marginal plates broad, tumid, alternating with the 

 Bupero-marginals in the basal half of the ray, coinciding with 

 them in the distal half; each with a stout sharp spine at its 

 upper (abactinal) end. 



Adambulacral plates distant, broad, each with a furrow- 

 scries of about twelve s])inelets, standing in an almo.st circular 

 palisade round a single large actinal spine. Mouth-plates 

 large, each with a furrow-series of six or seven spinelets, of 

 V inch the most central (adoral) is many times larger than any 

 of tlie others and slightly larger even than the large actinal 

 f;pine f f the ]jlate, and with a suture-.^erics of small spinelets. 



Actinal iikcrradial areas small, not extcndiiig beyond the 

 third adambulacral plate, and carrying oiil}' about six finely 

 spinate plates. 



Anus central, distinct. Madrepoi iform j/late small, situated 

 midway between the centre and the margin of the disk, and 

 out.side a very big paxilla. 



