[43] ' ALBATEOSS EXPLORATIONS. 545 



Lviuaii, Liitken, Duncan and Sladen, and others as 0. spinulosa^ from 

 iioitlieru waters. Lyman's deep-water specimens, some of which I have 

 examined, belong in part at least, to the following species. 



Ophiacantha fraterna Verrill, sp. nov. 



B. range, 908 to 1,G08 fathoms. Common. 



Disk rounded, rather swollen, with ten slightly raised radial ridges 

 made by the radial shields, which have the outer ends small, a little 

 ])rominent and naked. The surface of the disk is covered with very 

 small, short, obtuse, rough spinules, terminated by several minute 

 sharp thorns ; usually mixed with these there are many small, rather 

 rough conical granules, of about the same size. Arm -spines at base of 

 arms about eiglit, longest on the second and third joints beyond the 

 disk, but the rows are not closely approximated dorsally. The uj^per 

 spines are long, very slender, acute, and but slightly roughened ; the 

 middle ones are a little thorny ; the lower ones comparatively short. 

 Tentacle-scale flattened, small, tapered, subacute. Ventral arm-plates 

 narrow, about as long as broad, strongly convex on the outer margin, 

 and with a distinct angle on the inner. Mouth-shields small, trans- 

 versely cross-shaped, with a small outer lobe extending a little on the 

 interbrachial spaces, and with a small, very obtuse angle on the inner 

 margin, the side lobes much larger and more prominent. Side mouth- 

 shields rather wide, somewhat crescent-shaped, strongly curved. Mouth- 

 papillse about three on each side, besides a larger one below the teeth ; 

 they are rather long, spiniform,and acute, the outer one not diifering 

 from the rest. Color in alcohol dull brownish yellow, usually with 

 darker brown blotches on the arms and disk. Diameter of disk, usually 

 9 to 12'"'". 



This species has hitherto been confounded with 0. hidentata, which it 

 resembles. It differs in the smaller size and different character of its 

 disk-spinules, in the rougher spines, smaller and more acute tentacle- 

 scales, and in the sharp, spiniform, outer mouth-x)apilhie. The mouth- 

 shields have an outer lobe extending somewhat on the interbrachial 

 spaces, though less so than in 0. millespina and several other species. 



Opliiacantha varispina Verrill, sp. nov. 



B. range, 101 fathoms, off Nova Scotia. 



Disk slightly flve-lobed, covered on the central part with small, 

 elongated, tapered, acute, rough spines, which are gradually replaced 

 toward the margins by shorter and stouter, very rough, obtuse stumps, 

 surmounted by a group of sharp, rough spinules ; radial shields slightly 

 exposed at the prominent outer end. Arms slender ; the siMnes about 

 eight, somewhat rough, glassy 5 the uj)per ones long, slender, acute, 

 the rows nearly meeting on the second joint beyond disk; the lower 

 ones are shorter and very slender ; tentacle-scale flat, subspatulate, 

 broadly rounded at the end. Ventral arm-plates near base of arms not 

 much broader than long, rather pentagonal, the outer edge curved, or 

 H. Mis. 67 35 



