[45] 



ALBATROSS EXPLORATIONS. 



547 



Ophiacantha abyssicola G. O. Sars. 

 B. range, 1,000 to 1,608 fathoms, 1883. Not uDcommon. Very closely 

 allied to the next, and i)erhaps identical. 



Opliiacantlia millespina Verrill. 1879. 

 B. range, 100 to 1,917 fathoms, 1888. Abundant and widely diffused. 



Ophiacantha aculcata Verrill. 1885. 



B. range, 1,34G to 1,395 fathoms, 1883. 



A large species, with live unusually long, gradually tapering arms. 

 Disk rounded and swollen, throughout evenly covered with small, 

 slender, elongated spinules, having rough sides and terminated by four 

 to six slender, rough, divergent points. These disk-spinules are less 

 crowded, smaller, longer, and more slender than in 0. hidentata. End of 

 radial shields not exposed. Arm-spines very long, slender, nearly 

 smooth, eight or nine at base of arms, those next to the edge of disk 

 decidedly longer and forming an almost continuous band above. Ten- 

 tacle-scales rather wide, but with acute tips at base of arms, rapidly 

 becoming smaller and acute-lanceolate farther out. Mouth-shields 

 rather small, rounded externally, and not extending much on the inter- 

 brachial spaces, obtuse-angled on the inner side. Jaws broader and 

 more obtuse than in most species. Mouth-papillae rather slender, usu- 

 ally three or four on each side of a jaw, besides the median one ; the 

 outer one is largest, broad and flat at base, rapidly narrowed toward 

 the acute end ; the next two are more slender, spiuiform, and acute; 

 sometimes an additional smaller one stands out of line, behind those in 

 the regular row. Color, light orange or buff. Diameter of disk of a 

 large example, 17™"" : length of arms, 110^™. Stations 2034 and 2105, 

 in 1,346 to 1,395 fathoms, on Brisinga elegans V. 



Ophiacantha anomala G. O. Sars. 



B. range, 101 to 131 fathoms, off ISTova Scotia, 1883. Not common ; 

 chiefly northern. 



This species is easily recognized by having regularly six arms. The 

 disk is covered with rather large and coarse stump-like spinules, 

 rough at the obtuse or rounded summit. 



Ophiacantha spectabilis G. O. Sars. 



B. range, 131 fathoms, off Nova Scotia, 1883, One specimen only. 



This species has smoothish, tapering, acute spines on the disk. The 

 mouth-papillae are slender, tapering, and acute. 



Ophiacantha crassidens Verrill, Amer. Journ. Sci., February, 1885. 



B. range, station 2115, in 843 fathoms, off Cape Hatteras. 



This large species is easily distinguished by its disk, covered with 

 small, conical, acute spines, and bj' the remarkably large, rough, and 

 thick mouth-papillae, which are crowded. The arm-spines are rather 

 short and blunt. The color is dark brown in alcohol. 



