OPHIUROIDEA OF THE BAHAMA EXPEDITION. 60 



Whole upper surface of disk and arms and lower surface 

 of disk covered with thin, naked cuticle, wrinkled when dry, 

 in which are imbedded microscopic scales, on the disk, and a 

 row of small, but distinct, marginal scales. Sometimes there 

 are a few minute, acute granules along the margin and on 

 the bases of the arms. Radial shields narrow, very small, or 

 concealed by cuticle. 



Diameter of disk, 7 mm; length of arms, about 45 mm. 



Another slightly larger specimen from the same station 

 has the disk tumid, and the lobes extend out more on the 

 bases of the arms. The cuticle is thicker and contains num- 

 erous microscopic scales, while on the lower side of the disk 

 there are many very small, scattered, pointed granules. Sim- 

 ilar granules are scattered on the sides and back of the arms. 

 The lower side of the arms and disk is covered with thick 

 cuticle that conceals the plates, even when dry, unless treat- 

 ed with potash. 



The spines are usually four, but often three and four al- 

 ternately, short, rather thick, acute, rough, the upper one 

 largest, webbed together for half their length with cuticle. 



Mouth-papilla? four or five, flattened, rounded at the end, 

 and minutely serrate, except the outer one which is shorter 

 and scarcely serrate. On some of the basal joints there is 

 often a minute, slender, acute tentacle-scale, concealed by 

 cuticle in the alcoholic specimens. Under arm-plates and 

 oral shields as in the smaller one described above. 



Another specimen, with disk 8 mm. in diameter, from sta- 

 tion 15, has the oral shields more triangular, with rounded 

 corners, their breadth being about equal to the length. The 

 radial shields can be seen through the dried cuticle as very 

 small, narrow, oblong plates, well apart. 



Mouth -papillae five, small, serrate, decreasing in size dis- 

 tally. Arm-plates and spines as in the others. 



Station 4, off Havana, in no fathoms; station 15, off Ha- 

 vana, in 200 fathoms; station 24, off Key West, in 60 fathoms. 



