Narrativi-: of Bahama Expedition. 221 



face, and very lloht buff\-, almost white, on the lower side. 

 Arm-spines small, the upper being the longest. Three re- 

 markabh' pretty species of OpJiluthrix were collected. One 

 was bluish violet in color, with a disk covered with forked, 

 stumpy spines, and a few long, slender, needle-like spines. 

 This species is beautifully marked, the disk with sharp, radi- 

 ating lines of purple and white, and the arms with pairs of 

 pure white lines enclosing bands of deep cobalt blue. Arm- 

 spines six, the uppermost being the longest. Another Ophi- 

 othiix was blue, the disk without long spines, but thickly 

 beset with trifid stumps. This species was ornamented by 

 transverse series of white blotches between the upper arm- 

 plates, and round, white blotches on the under arm-plates. 

 Arm-spines seven, the lowest furnished with booklets. The 

 third species of this genus is probably O. siiciisoiiii Liitken, an 

 exquisitely beautiful object under a lens of moderate power- 

 The disk is beset with exceedingly long, glassy spines,, 

 arranged along ten radiating lines, and is of a delicate laven- 

 der color, with ten sharp, radiating lines of purple running in 

 pairs from centre to circumference, each pair enclosing a band 

 of light violet. There are four concentric purple lines run- 

 ning around near the upper edge of the disk. The lower sur- 

 face is marked by similar concentric lines of white and purple 

 alternating. Along the upper side of each arm runs a purple 

 band between two fine white lines. On the under surface a 

 similar band extends from the tip of the arms to the mouth. 

 But the most striking feature of this remarkable form is the 

 arm-spines, which are the longest of any in the collection,, 

 being nine times as long as the arm-joints. As usual in this 

 genus, these spines are glassy, with a row of spinelets on each 

 side. A species of Ophioiny.xa, from which the label is lost,, 

 but which is associated with the serpent-stars from this local- 

 ity, is of a buffy white color, with comparatively long arm- 

 spines. Several specimens of a species, which can probably 

 be referred to the genus Sigsbcia, were secured at this time. 

 They were smaller than S. murrhiiia of Lyman, or the Sigsheia 

 mentioned in the account of the Havana collections, page 79;^ 



