OPHIUROIDEA OF THE BAHAMA EXPEDITION. 51 



runs the whole length of the arm; a narrow whitish transverse 

 band marks the inner edge of the side arm-plates, and some- 

 times both edges are bordered with white. One example, 

 from the Blake Expedition, in alcohol, has a very distinct 

 white dorsal line on the arms, and they are also crossed by a 

 few broad white bands. The ground-color of the arms and 

 disk, above, is light chocolate-brown; beneath, nearly white. 

 Diameter of the disk of the largest specimen described above, 

 11 mm. 



Stations 13 and 15, off Havana, in 200 fathoms, two ex- 

 amples. Taken at many stations by the Blake, in 82 to 955 

 fathoms. 



Ophiotreta Verrill, subgenus (See p. 44). 



Ophiopristis (Oft/i/otreta) lineolata (Zywz.) 



Ophiacantha lineolata Lyman, Bull. Mus. Comp. Zool., Vol. X, p. 258, 



pi. VI, figs. 79-81, 1883. 

 Ophiacantha, sp., Nutting", Narrative, p. 81, (color). 



An excellent specimen of this rare and beautiful species is 

 in the collection. Only a single specimen was taken by the 

 Blake Expedition and described by Mr. Lyman. Although 

 there can be no doubt as to the identity of our specimen with 

 this species it differs in several particulars from Mr. Lyman's 

 figures. These differences are, no doubt, partly individual 

 variations, but others are probably due to errors in 

 the figures, for the latter do not agree well with the descrip- 

 tion, especially as to the spines. Our specimen has, on some 

 of the arms, two tentacle-scales to a pore, on at least ten 

 joints, instead of only on one joint. The mouth-papilla; and 

 tooth-papillae are somewhat differently arranged. The under 

 arm-plates and especially the adoral shields do not agree with 

 the figures. The upper arm-plates are wider but of the same 

 character. The six or seven arm-spines are nearly smooth 

 and terete and evenly tapered, without any serrulations vis- 

 ible with a lens. They have a fine silky appearance quite 

 unusual in this group, but they are figured as distinctly ser- 

 rulate or thorny. 



