a 



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



Table of Species of OpMocoma — continued. 



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



Mouth shields elongated. Upper arm plates narrow, . . . OpMocoma riism. 



First or second arm spine longest. Arms longer and structure lighter than ) ^ 7 ■ •, 



.. '^. ° ° ° > (Jviiiocoma pumiia. 



in preceding species, . . . . . . . J ^ ^ 



Third and fourth arm spines longest, similar to preceding, . . . OpMocoma valencice. 



Similar to preceding, but arms narrower, and mouth papillae and tentacle ) Qpj^{^gQ,j^^ alexandri. 

 scales less stout, ....... \ ^ 



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



Tooth papiUse very numerous. An extra scale spine at base of upper arm spine. 1 q j^Iq^q,^^ papillosa. 

 Tentacles papillose. [Belongs with OpMopteris ?], . . . • J r r • 



Arm spines hollow as in OpMacantha, \ 



but having otherwise the characters > OpMocoma nigra. 



of OpMocoma. • j 



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



, ^ . ^ , . . ' ■' >• OpMocoma rascMi. 



close to Opmoeoma nigra. J -^ 



OpMocoma scolopendrina, Agas. (PI. XLVII. fig. 3). 



OpMocoma Scolopendrina, Agas., Mem. Soc. Sci. Nat. Neuchatel, vol. i. p. 192, 1835 ; Miill 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. 



OpMura scolopendrina, Lmk., Hist. Anim. sans Vert., vol. ii. p. 544, 1816. 



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



OpMocoma 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 OpMocoma 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. 



OpMocoma erinace^is, Miill. & Tr., Syst. Ast, p. 98, 1842 ; Ltk., Addit. ad Hist., 

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



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



Honolulu Reefs ; Samboangan Bank. 



