NORTH PACIFIC OPHIUEANS IN NATIONAL MUSEUM CLARK. 



169 



lar to that so characteristic of Atn phiodia digitula. First imdor arm 

 plate minute, squarish; succeeding plates somewhat hexagonal or 

 pentagonal, about as wide as long, more or less in contact on basal 

 part of arm; on many of them there is a minute tooth or sharp pro- 

 jection at the center of tlie distal margin. Side arm plates small, each 

 with only three sharp, subecjual spines, about as long as the joint or a 

 little longer. Tentacle scales, two. Color (dried from alcohol), nearly 

 white, or light grayish-brown; upper and under arm plates some- 

 tunes rather heavily shaded with dull brownish-red. 



Localities. — Albatross station 3695, off Tsuragi Saki Light, Honshu 

 Island, Japan, 110 t(^ 259 fathoms, green mud, fine sand, 30 speci- 



FlG. 



AMPHIOPLVS ACANTHINUS. X4. a, FROM ABOVE; ft, FROM BELOW; C, SIDE VIEW OF THREE 

 ARM JOINTS NEAR DISK; d, REGENERATED DISK AND THREE REGENERATED ARMS. 



mens; station 5073, Suruga Gulf, lat. 34° 46' N.; long. 13S° 21' 50" 

 E., 148 fathoms, gray mud, bottom temperature 54.6°, 2 specimens. 



Type.—C2ii. No. 25595, U.S.X.^M., from station 3695. 



This is an unusually well-characterized species and yet its generic 

 position is somewhat in doubt. As an AmpMoplus it ought not to 

 have spines on the disk, while, on the other hand, it will not go into 

 Verrill's genus AmpMlimna, where spiny-disked species of AmpTiio- 

 plus ought to go, for it does not have "six to ten" arm spines, nor are 

 the tentacle scales "spiniform," nor are the radial shields "parallel, 



