REPORT ON THE OPHIUROIDEA. 275 



Astrosehema horriduni, Lym. (PI. XXX. figs. 1-4). 



Asiroschema horridimi, Lym., Bull. Mus. Comp. Zool., vol. vi., part 2, p. 66, pi. xvii. figs. 

 458-461, 1879. 



Entire surface covered with little, swollen, oblong angular plates or scales, bearing 

 minute points. 



(Type specimen from Station 170.) Diameter of disk 12-5 mm. Length of arm 

 195 mm. Width of arm near disk 47 mm.; height of arm 4-2 mm. Seven stout, 

 thickened, rather small teeth, of the usual short spearhead shape. The mouth angles are 

 paved with large, flattened, swollen grains, but have no true papillae. Arms nearly cylindri- 

 cal, very slightly swollen for their first 20 mm., beyond which they taper very regularly. 

 They arc evenly and pretty closely beset with minute points, like little blunt spines, 

 about 4 in the length of 1 mm. ; these, on allowing the surface to dry, are seen to stand 

 on small, swollen, oblong, angular plates or scales, which may be considered as exaggerated 

 grains set with points. Tliis covering continues quite to the end of the arm, where, 

 however, the grains are more rounded and without points. Disk thick, rising a little 

 above the arms, elegantly scalloped on its margin, with large radial shields (ribs), which 

 are thick, swollen, and projecting at their outer ends, and taper inward to the centre 

 where they meet ; its surface is paved with little oblong, angular, swollen plates or 

 scales, rather coarser than those of the arms, and bearing similar minute points. Genital 

 openings straight, and occupying about one-half the height of the disk. Mouth tentacles 

 enclosed m a tube of flat grains ; the next pair has no tentacle scale ; the next one 

 and those beyond have two, which are short at first, but about 40 mm. out become 

 somewhat suddenly elongated, the upper one, about 1 -3 mm. in length, remaining blunt, 

 spmiform, while the lower and larger takes on the form of a cylinder 3 mm. long, wath a 

 rough, swollen end. The two lines of pores lie closer together than usual, so that the 

 furrow on the lower side of the arm is narrow. Colour in alcohol, pale reddish-brown. 

 Station 170.— July 14, 1874 ; lat. 29° 45' S., long. 178° 11' W. ; 600 fathoms. 



Astrosehema tumidum, Lym. (PL XXIL figs. 8-12). 



Astrosehema tumidum, Lym., Bull. JIus. Comp. Zool., vol. vi., part 2, p. 68, pL xvii figs 

 450-453, 1879. 



Disk and arms covered by regularly spaced, pointed, conical grains. The bases of the 

 arms for two or three joints are strongly swollen. 



(Tyi^e specimen from Station 192.) Diameter of disk 8 mm. Length of arm 

 135 mm. Greatest width of arm close to disk 37 mm. Width beyond the swelling 

 2-3 mm. Height of arm at same point PS mm. Seven or eight short, flat teeth, with 

 a curved cutting edge ; the lowest one smallest. The general granulation of the disk is 

 continued in a somewhat coarser form over the mouth angles, and up theii- sides ; but 



