MUSEUM OF COMPAKATTVE ZOOLOGY. 275 



Ophiochondrus crassispinus sp. nov. 



Plate VII. Figs. 111-113. 



Special Marks. — Seven or eight thick, short, blunt, slightly rough arm-spines. 

 Radial shields long and prominent. Mouth-papillae sharp and separated. 



Description of an Individual. — Diameter of disk 6 mm. Length of arm 

 20 mm. Width of arm close to disk 2 mm. Three short, stout, sharp mouth- 

 papilla? on each side of an angle, and one similar but larger at the apex; this 

 last may be considered as the lowest tooth. Mouth- shields somewhat swollen, 

 about as broad as long, with an angle inward. Side mouth-shields large, thick 

 and wide; broader without than within where they meet. First under arm- 

 plate small, longer than broad, with an angle inward. Those beyond are sep- 

 arated one from another, and are four-sided and much wider than long, with a 

 slight re-entering curve without. Side arm-plates with narrow, prominent 

 spine-ridges; meeting below but separated above by fan-shaped upper arm- 

 plates which present a truncated angle inward. Disk thick, sparsely beset 

 with a fine granulation, except on the radial shields which are prominent and 

 large; they are much longer than broad, wider without than within, and sepa- 

 rated; their ends are rounded; length to breadth, 2 : .6. Seven or eight short, 

 blunt, slightly rough arm-spines, which stand at a considerable angle to the 

 arm; they are nearly equal and not so long as a joint; those in the middle 

 often are swollen at their base. No tentacle-scales. Color in alcohol, pale 

 straw. 



Station 316, 32° 7' N., 78° 37' 30" W., 229 fathoms, 1 specimen. 



This species is well distinguished from 0. stelliger by its great naked radial 

 shields and numerous arm-spines; and from 0. convolutus by different mouth- 

 papillse and no tentacle-scale. 



Ophiochondrus squamosus. 



Plate VII. Figs. 108-110. 



Special Marks. — Disk covered above by thick, lumpy, separated plates, and 

 below by lumpy scales. Seven or eight short conical arm-spines. Lower arm- 

 plates obscured by thick skin. 



Description of an Individual Diameter of disk 0.5 mm. Length of arm 



40 mm. Width of arm near disk without spines 1.3 mm. Three small, some- 

 what flattened, separated papillae on each side of a mouth-angle, whose apex i< 

 occupied by the lowest tooth, which is large and of a wide spear-head shape. 

 Mouth-shields small, of a transverse oval form: length to breadth, .8 ! ,9, 

 Side mouth-shields scarcely visible under the thick skin ; they are narrow and 

 meet within. Basal under arn>platee obscured by thick skin; farther out on 

 arm, they appear as thick, widely separated transverse oval plates, and near 

 the end they are squarish and nearly or unite touch each other. Side arm- 



