Indian Deep-sea Asferoi'dea, 115 



delimited frotii tlic rays, witli wliicli it is flush, by a groove 

 that ])as>es across the base of each ray. Rays long, semi- 

 cylindrical, constricted laterally, as well as somewhat 

 do])rc.~sed, ncfir their junction with the disk. 



Abactinal surface closely covered with partly imbricate 

 cruciform plates which have no particular arrangement on 

 the disk, but which on the rays stand in beautifully regular 

 longitudinally and transversely parallel rows forming a 

 quadrangular network of great symmetry. There are from 

 twelve to fourteen longitudinal rows of plates on each ray 

 between the adambulacrals. All the plates are embedded in 

 a continuous membrane, and each plate carries at tlie decus- 

 sation of its cross-pieces a stout erect spinelet. The mem- 

 brane that closes over the quadrangular meshes between the 

 plates is thickly studded with large pedicellaria3 and is 

 perforated by papuke— one to three in each mesh. 



Marginal plates quite undifferentiated. 



There are no actinal plates, the actinal surface of the 

 rays being almost entirely taken up by the broad ambulacral 

 furrow. 



The adambulacral plates are very small ; each plate carries 

 two long cylindrical truncated spines placed transversely, tlie 

 outer spine being about twice the length and four times the 

 t!)ickncss of the inner one, and usually having external to its 

 base a large pedicellarin. 



Although the ambulacral furrow is so broad the tube-feet 

 are biserial. 



Madrej)oriform plate small, radially striated, placed near 

 the margin of the disk. 



Colour uniform jet-black. 



Andaman Sea, 240 to 220 fathoms, coral- sand and forami- 

 niferal ooze ; Bay of Bengal, 290 fatiioms. 



Family Asteriidse. 



ASTERIAS, Linn. 



Subgen. Stglastekias, Sladen. 



50, Asterias mazophorus, Alcock and Wood-Mason. 



Aslerids mazophorus, Ann. & Mag. Nat. Hist., Dec. 1801, p. 436. 



Hays 5. E,= ll r. E=115 millim. in the 

 type specimen. 



Disk extremely small, circular (button-like), delimited 

 abactinally from the rays, beneath the level of whicii it is 



