112 Mr. A. A 1 cock on 



which last are often quite smooth and unarmed ; (iv.) the 

 anal aperture is very distinct. 



This subgenus shows an interesting series of gradations 

 between Zoroaster, Wyville Thomson, and Cnemidaster, 

 Sladen. At the true Zoroaster extreme is Zoroaster Gilesu, 

 with all the plates spinate and armed, with numerous pedi- 

 cellarise, and with a broad ambulacrum and four rows of tube- 

 feet. Near the Cnemidaster extreme comes, as Mr. Sladen 

 has already pointed out, Z. Sigsheei, with the abactinad plates 

 smooth and unarmed and only the actinad plates spinate, with 

 few pedicellaria3, and with crowded tube-feet which only in 

 the basal part of the ray are quadriserial. "While between 

 the two come (i.) Z. squameus, with the abactinad plates 

 granular or quite smooth and their armature reduced to one 

 deciduous spinelet, and (ii.) Z. zea, in which the abactinad 

 plates are quite smooth and unarmed and the pedicellariaj 

 reduced in size and number. 



Family Pterasteridge. 

 Marsipaster, Sladen. 



45. Marsipaster Mrsutus, Sladen. 



Marsipaster hirsuttis, Sladen, ' Challenger ' Asteroidea, p. 487, 

 pi. Ixxviii. figs. 3 find 4, pi. Ixxix. figs. 4 and 6 ; and in Wood-Mason 

 and Alcock, " Indian Deep-sea Dredging," Ann. & Mag. Nat. Hist., 

 Dec. 189], p. 437. 



Bay of Bengal, 1997 fathoms, Glohigerina-oozQ and 

 pumice. 



Hymenaster, Wyville Thomson. 



46. Hymenaster nohilis, Wyville Thomson. 



Hymenaster nohilis, Wyville Thomson, Journ. Linn. Soc, Zool. 

 vol. xiii. p. 73, fig. 11 ; Sladen, ' Challenger ' Asteroidea, p. 495, 

 pi, Ixxxvii. figs. 1-3 ; and Wood-Mason and Alcock, " Indian Deep- 

 sea Dredging," Ann. & Mag. Nat. Hist., Dec. 1891, p. 438. 



Bay of Bengal, 1748 fathoms, Olohigerina- oozo. and 

 pumice. 



Family Echinasteridse. 



Cribrella, Agassiz, Forbes. 



47. GribreUa prcestans, Sladen. 



Cribrella prcBstans, Sladen, 'Cballenger' Asteroidea, p. 545, pi. xcvi. 

 fig. 7, pi. xcviii. figs. 7 and 8. 



Four specimens from the Andaman Sea, 240 to 480 



