132 THE VOYAGE OF H.M.S. CHALLENGER. 



Amphiura iris, Lym. (PL XVI. figs. 4-6). 



Am [ih i ura iris, Lym., Bull Mus. Comp. Zool., voL vi., part 2, p. 23, pi. xi. figs. 302-304, 1879. 



Disk scaled above and below ; one large oval tentacle scale ; four long arm spines, 

 the uppermost and lowest longest. 



(Type specimen from Station 236.) Diameter of disk 5 mm. Width of arm without 

 spines 1'2 mm. One short, stout, somewhat flattened blunt papilla on each side of the 

 mouth angle, and a pair, similar, but somewhat smaller, at its apex. The large and 

 broad scales of the first pair of tentacles are low down and conspicuous. Mouth shields 

 of a very wide heart shape, much wider than long, with a rounded angle within. Side 

 mouth shields thick, long, triangular, tapering inward where they do not meet. First 

 under arm plate usually large, of a diamond shape, with its angles more or less truncated ; 

 the plates beyond are longer than wide, with outer side curved and widest, lateral sides 

 re-enteringly curved and a truncated angle within. Side arm plates stout, and rather 

 prominent, meeting neither above nor below. Upper arm plates fan-shaped, with inner 

 angle more or less rounded, or truncated, and outer side gently curved. Disk covered 

 above and below, with moderately coarse, crowded, irregular scales, those of the inter- 

 brachial spaces being more elongated, and those on the under surface somewhat obscured 

 by skin. Toward the centre of the disk there are seven or eight scales in the length of 

 1 mm. Radial shields much longer than wide, slightly curved, somewhat swollen, taper- 

 ing at both ends and widest in the middle ; separated their whole length by a row of 

 three or four large scales ; length to breadth, 2 : "6. Four long, cylindrical, tapering arm 

 spines, whereof the uppermost and lowest are longest, and equal to one and two-third 

 arm joints. One large tentacle scale. Colour in alcohol, pale grey. 



Station 236.— June 5, 1875 ; lat. 34° 58' N.,long. 139° 30' E. ; 420 to 775 fathoms; 

 mud. 



Amphiura tomentosa, Lym. (PL XXIX. figs. 10-12). 



Amphiura tomentosa, Lym., Bull. Mus. Comp. Zool., voL vi., part 2, p. 23, pi. xi. figs. 299-301, 

 1879. 



Disk scaled on both sides with rather large, spaced scales ; those below somewhat 

 obscured by thick skin ; four tapering, equal arm spines ; no tentacle scale. 



(Type specimen from Station, Balfour Bay, Kerguelen Island.) Diameter of disk 

 6 "5 mm. Width of arm close to disk, without spines, 1 mm. One very small short 

 mouth papilla, often obscured by skin, on each side of the mouth angle, and a pair, 

 larger and rounded, at the apex. Mouth shields irregular, small, rounded triangular, 

 with a small peak inward. Side mouth shields longer than broad, wider without than 

 within, where they just meet ; both they and the mouth shields are somewhat obscured 

 by skin. Under arm plates narrow, longer than broad, pentagonal, with a blunt angle 

 inward, small re-entering curves on the lateral sides, and outer lateral corners rounded. 



