170 THE VOYAGE OF H.M.S. CHALLENGER. 



Table of Species of Ophiocoma — continued. 



At base of arm, sometimes two tentacle scales. Upper arm plates wide, . Ophiocoma cethiops. 



Mouth shields elongated. Upper arm plates narrow, . . . Ophiocoma riisei. 



First or second arm spine longest. Arms longer and structure lighter than \ q i- •/ 



in preceding species, . . . . . . • J 



Third and fourth arm spines longest, similar to preceding, . . . Ophiocoma Valencia. 



Similar to preceding, but arms narrower, and mouth papillae and tentacle 1 „ , . , , . 



scales less stout, . . . . . . • J 



Some arm spines flattened like a spatula, ..... Ophiocoma canaliculata. 



papillae very numerous. An extra scale spine at base of upper arm spine. ) Qvhiocoma papillosa 

 entacles papillose. [Belongs with Ophiopteris ?], . . . . / * r r 



Tooth 



Tentacles 



Arm spines hollow as in Ophiacantha, 

 but having otherwise the characters 

 of Ophiocoma. 



Ophiocoma nigra. 



Arm spines doubtless hollow, as it is very ) „ , . , .. 



, r , „ ,. . ' J > Ophiocoma rasch it. 



close to Ophiocoma nigra. j * 



Ophiocoma scolopendrina, Agas. (PI. XL VII. fig. 3). 



Ophiocoma Scolopendrina, Agas., Mem. Soc. Sci. Nat. Neuchatel, vol. i. p. 192, 1835 ; Mull and 

 Tr., Wieg. Archiv, voL vi. p. 328, 1840 ; Syst. Ast., p. 101 ; Ltk., Addit. ad Hist., part 2, 

 p. 163 ; Lym., 111. Cat. Mus. Comp. Zool., No. i. p. 87 ; Ludwig, Anatomie der Ophiuren, 

 Zeits. fur Wissen. Zoologie, vol. xxxi p. 241. 



Ophiura scolopendrina, Link., Hist. Anim. sans Vert., vol. ii. p. 544, 1816. 



Ophiocoma molaris, Lym., Proc. Bost. Soc. Nat. Hist., voL viii. p. 79, 1861. 



Ophiocoma alternans (young?), V. Mart., Oph. Ind. Oc. Wieg. Archiv, voL xxxvi. p. 251, 1870 ; 

 Lym., Bull. Mus. Comp. Zool., vol. iii., part 10, p. 225. 



So many variations in colour, length of arms, and character of spines are found, that 

 Dr. Ludwig was impelled to combine it with Ophiocoma erinaceus. The two are how- 

 ever distinguished by the large central disk scales of the latter. The position of the 

 interior organs is figured in Plate XLVII. 



Simons Bay, Cape of Good Hope ; 10 to 20 fathoms. Tongatabu Reefs ; 18 fathoms. 

 Samboangan Bank ; Zebu Reefs, Philippines, Fiji Islands. 



Ophiocoma erinaceus, Mull. & Tr., Syst. Ast, p. 98, 1842 ; Ltk., Addit. ad Hist., 

 part 2, p. 164 ; Lym., 111. Cat. Mus. Comp. Zool., No. i. p. 85. 



Ophiocoma tartarea, Lym., Proc. Bost. Soc. Nat. Hist., vol. viii. p. 78, 1861. 



Honolulu Reefs ; Samboangan Bank. 



