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



Table of Species of OjyJiiacantha — continued. 



' About eleven mouth papilla to each angle ; large ) Qpj^i^,g^,^tj,a cuspidata. 

 tentacle scales, . . • • j 



Seven mouth papiUffi to each angle ; slender .spini- ) Q^j^iacantha longidms. 

 form tentacle scales, . . . • ) 



Mouth papillae, long and - 

 slender. 



I 



CD 



o 



Seven mouth papilla.. High disk stumps with \ 



tliorny sides and ends. Arm spines feebly > OpMaeanfha nodosa. 

 thorny. Six arms, . . . • j 



The lowest arm spine thickened and curved, ..... OpMaranfha corimfa. 



Tentacle scales with long thorns ; arm spines strongly thorny, . . Ophiacantha aspera. 



Nine rather short, scarcely thorny arm spines. Side arm plates barely meeting \ _ ^ 



above and not prominent, so that the upper arm spines on either side , Ophiacantha indica. 

 are widely separated. Disk crotchets close-set and rather coarse, . ) 



Seven strongly thorny arm spines. Side arm plates very prominent. Coarse ) Q^j^ifj^^antha steUata. 

 disk crotchets, . . . . • • • • i 



Arm spines strongly thorny ; tentacle scales long, stout, and sharp, . . Ophiacantha scidata. 



Eight or more feebly thorny arm spines; side arm plates not very prominent. ) g^j^f^^.f^^^^j^^ cosmica. 

 Disk crotchets rather stout, . . . • • • I 



Ten slightly thorny arm spines, longer than in Ophiacantha cosmica, . Ophiacantha viillespina. 



Seven to eight slender, nearly smooth arm spines. One narrow spine-hke \ 



tentacle scale. Under arm plates much wider than long of a broad axe- / Ophiacantha discoidca. 

 shape, . . . • • • • • • ' 



Seven scarcely thorny arm spines; side arm plates very prominent.' Disk \ Q^j^iacantha pentacrimi.-^. 

 crotchets minute, . . . • • • -J 



Six not thorny, rather short arm spines; side arm plates not very prominent. ) Ophiacantha ahyssicola. 

 Disk crotchets tine and close-set, . . . ■ ■ J 



Very long, not thorny arm spines ; side arm plates large and swollen ; outer ) Q^j^iaranthu Icvispina. 

 side of under arm plates strongly curved, . . . • 1 



Disk evenly set with minute bifid or trifid stumps. Four- to five sharp, slightly ) Ophiacantha daUasi. 

 rough, glassy arm spines, not as long as a joint, . . . • j 



Disk beset with minute grain-like stumps bearing a crown of blunt thorns. Ai-m \ 



spines long, slender, translucent, and thorny, mounted on very projecting ^ Op>htacantha seirafa. 

 side arm plates which meet above, . . . . • • ) 



Disk covered vnth. soft skin, through which a fine scaUng may be distinguished ; \ 



and set above with a few pointed, rough, stout spmes. On each angle, tleven ( Ophiacantha marsupial is. 

 scattered spine-like mouth papillee. Three slender, nearly smooth, rounded, ( 

 tapering arm spines, . . . . • • • • / 



-a 



