SEHl'Kyr STA/iS. 



lol 



cordi/'e)xt, a incnilicr of a iicims nearly i-clatcil tn Ai/iji/iii/ni. is |ilciiriful in the liarhur 

 uf Charloston, S. C, .in.! is apiiarmtly \ i\ ipanms, since it may lie found with tuiiiute 

 yonni;' i-linL;ini: to liic arms ami disc. 

 Il oc-uis als,, in th.' W.'st Indi.'s. 



<>j'/ni,ri/„i/nin,i r,irrnii>si/ii/. taken 

 li\ tlic •Challen-vr" east of Kei'Linelen 

 island, is remarkalile for llie manner 

 in uiiieli the disc, wlneli is scarcely 

 attached to the arnrs. nnd is entirely 

 eoNcred with small scales, oxcrlics thi' 

 arms "like a i;asi|n<' ca[i."" (J^i/u'd- 

 rvnia <i tin, ,!,.•< .'in<l O. ,(l,.niii<lti, are 

 lai-^t' sjieeii'S from the west coast of 

 North America, .\moni; the Litaiera 

 with nunicrons lon^:. nsualh roni;h or 

 thorny, arm spines the principal ai'c 

 OphiiiciiitliK with tliirly-nine de- 

 scriUed specii's, and (>iJi.lnl/ir(.r, with 

 tifty-si\ species. The species of 

 O/ilu'C-aNf/Hi cm he rc.idily distin- 

 i;-iiishc<l from each other hy points of 

 intern.il and e\ternal strncture. 'I'hc 



FlC. l.iL'. — <lj,liiH,:ii,lhii rll,-l,,.i 



\ru\ spines \ary fron\ fonr to eleven in num- 

 herat each arm joint. ''A /■//■/)/f//v^ which 

 is widely spi-c.ad in tile soutlieni ocean, 

 occurring at depths varyint; from '20 to 600 

 fathoms, carries its yininLi, till tliey are quite 

 larg», in the ovarial Inirsa oi- pouch, whence 

 tliey often tlirnst an arm throutili the gen- 

 ital openiuii'. 'Ilic liuisa' art' pleated bags 

 liaviii^- lime scales in their substance and 

 adlierinu' to the thickened wall of the diges- 

 tive cavity. Some of the basal arm spines 

 of Ojihim/iiffif (llpsacos dredged by tlie 

 'Cindlenger " off Culebra, West Indies, in 

 •■JOII fatlionis, are from five to seven times 

 IrV^ the length of the arm-joint. The species 

 of Ophiothrl.i- are exceedingly diftieult to 

 distinguish from each otlier, although the 

 genus is well marked liy the very large 

 1^ lliree-sided radi.al shields, disc set witli 

 thorny gr.ains; fi\-e to ten nlass\' sjiines 

 (lieset with thoiais, and often three times as 

 >ng as the joints), on eacli arm joint ; single, 

 small, spiiu'-like tentacle scales on each arm- 

 it ; swollen inlerbracliial spaces; and 

 want of pci-fcci union between the halves 

 of each mouth-fr.nne. 'I'he vcrli'ln-a' of the arms h.ive :i |)eculiar projection which in- 

 terlocks into a slot in the preceding bone, thus gi\ ing a fulcrum (says Lyman) for the 



Fin. l.«. — Opluallinx frat/ilie. 



