Boone, Echinodermata, Gruises of "Eagle" and " Ara" 1921-28 111 



Ophiothrix suensonii Lutken. 

 Plate 64. 



Type: Collected in the West Indies, on Gorgonian; deposited in 

 the Copenhagen Museum. 



Distribution : Florida, Bahamas, Cuba, Jamaica, Haiti, St. Thomas, 

 Dominica, St. Vincent, Grenada, Barbados, Venezuela. 



Material examined: Two dry specimens, Pigeon Key, Florida, 

 April 17, 1923, Cat. no. 212. Two young specimens, Turtle Harbor, 

 Florida, 2y 2 fms., April 19, 1922. One, from the south of Catalina 

 Creek, Cuba, February 14, 1923. Two, from Barnet Harbor, 

 Bahamas, January, 19 , field tag 12. All collected by the "Ara." 



Color: This brittle star is usually a delicate lavender with a line 

 of deep purple bordered with creamy lines running down each arm 

 and with radiating lines of purple on the disk. The spines are glassy, 

 ornamented with tiny barbules along the edges, and banded trans- 

 versely with deep lavender and creamy rings. 



Life history : Apparently not yet studied. 



Technical description: Disk pentagonal, diameter 10.5 mm., arm 

 length 54 mm. Almost the entire abactinal surface is covered by the 

 radial shields except a narrow band on the interradial region separat- 

 ing the pairs of radial shields and supporting a series of long, slender 

 spines which are set in approximately three rows ; these spines also 

 occur on the center of the disk, also in a single line between the two 

 radial shields of each pair. The radial shields are large, naked, 

 occupying almost the entire dorsal surface of the disk ; each shield is 

 triangular with the apex directed inward, reaching almost to the 

 center of the disk ; the entire margin presents an acute angle terminat- 

 ing in a rounded peak. The interbrachial region of the actinal surface 

 is covered with tough skin and bears several spines similar to those 

 of the dorsal surface but much smaller. The genital slit is long, 

 extending from the mouth-plate angle to the lateral margin. The 

 mouth-shields are broadly nearly oval, or heart-shaped, with the outer 

 margin rounded, the inner produced to a small peak; the width of 

 the shield is twice its length. The side mouth-shields are short, 

 triangular with the corners rounded, meeting within. Tooth papillae 

 18, arranged in an oval figure, the outer ones the longest, the inner 

 ones shorter. There are four teeth, the uppermost one the longest, 



