Narrative of Bahama Expedition. 221 



face, and very light buffy, almost wliite. on the lower side.. 

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

 markably pretty species of Of>hiothrix 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 Op/ii- 

 otJin'x was blue, the disk without long spines, but thickly 

 beset with tritid 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 probablv O. snciiso)iii 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 tine 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 OpJiiomyxcu from which the label is lost, 

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

 ity, is of a bulfy white color, with comparative!}' long arm- 

 spines. Several specimens of a species, which can probably 

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

 They were smaller than S. viitrr/iiiur of Lyman, or the Sigsbda 

 mentioned in the accovmt of the Havana collections, page 79? 



