442 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. [1885. 



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, transversely 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-papillae about 

 three on each side, besides a larger one below the teeth ; they are rather 

 long, spiniform, and acute, the outer one not diflfering 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. bidentata, which it 

 resembles. It difiers 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-papillae. The mouth- 

 shields have an outer lobe extending somewhat on the interbrachial 

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



Taken at numerous stations by the Fish Hawk and Albatross in 908 

 to 1,G08 fathoms. Common. 



Ophiacantha varispina Verrill, sp. nov. 



Verrill, Report U. S. Fish Com. for 1883, p. 43, 1885. 



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

 gated, tapered, acute, rough spines, which are gradually replaced toward 

 the margins by shorter and stouter, very rough, obtuse stumps, sur- 

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

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

 eight, somewhat rough, glassy; the upper ones long, slender, acute, 

 the rows nearly meeting on the second joint beyond the 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 

 subtruncate in the middle, the inner edge nearly straight or slightly 

 angulated centrally. Mouth-shields strongly four lobed, the inner angle 

 acute, with concave sides, the lateral lobes prominent, subacute, the 

 outer lobe smaller, obtuse, extending somewhat on the interbrachial 

 area; side mouth-shields wide, not very long, somewhat crescent-shaped, 

 the outer margin convexly arched to fit the concave sides of the mouth- 

 shield. Mouth-papillae mostly flat and broad, lanceolate or obtuse, three 

 or four on each side besides the infradental ; a slender, smaller one 

 often stands out of line, back of the outermost, which is flatter and 

 more obtuse than the others. Color yellowish brown, with darker 

 blotches on disk and arms. Diameter of disk, 9'"°^ ; length of arms, 



Peculiar in the mixture of sharp spines and obtuse thorny stumps on 

 the disk. General appearance much as in 0. bidentata. 

 Off Nova Scotia, station 2069, in 101 fathoms. 



