NO. 2 ZIESENHENNE: NEWOPHIURANS 11 



Types. — Holotype, AHF no. 9; 7 paratypes, one in M.C.Z. 



Type locality. — Station 863-38, clinging to red coral, 30-50 fms., off 

 Bahia Honda, Panama, March 1, 1938. Five additional paratypes from 

 Station 948-39, 30-35 fms., off Bahia Honda, Panama, March 28, 1939. 



Remarks. — This species is closely related to S. lineata L. & M. of 

 Cocos Island and the Galapagos Islands but differs in the flat disk scales, 

 less swollen arm plates, and the very different color pattern. From 5. 

 murrhina Lyman of the West Indies, it differs markedly in the same 

 characters and in its much smaller size and more slender form. Its dis- 

 tinctive characteristics besides the color pattern are: irregular disk scales 

 with no rosette, knobs, or noticeable convexities; uppermost arm spine, at 

 least on basal segments, flat, longest at the upper margin, not quite so 

 large as the other two spines together, and not twice so wide as long. The 

 name laevis has reference to the smooth disk scales. 



Ophiacanthidae 



Genus OPHIACANTHA IVIuller and Troschel 



Ophiacantha phragma, new species 



Plate 2, Figs. 4-6 



Description. — Disk diameter, 8 mm. ; arms, about 38 mm. long. Disk 

 pentagonal, rather thick, covered with closely compacted, short, rounded 

 granules. Irregularly placed are some long, stout, pointed disk spines, 3^ 

 mm. in length. Radial shields concealed. Disk granulations extend out on 

 the first few upper arm plates. 



First upper arm plate small, partially concealed by granules. Suc- 

 ceeding plates longer than broad, somewhat hexagonal, proximal margins 

 straight, distal lateral and proximal lateral margins nearly straight, distal 

 margins slightly concave; distally the plates become triangular, longer 

 than broad, with a convex distal margin. Upper plates in contact basally, 

 separated by the side arm plates distally. Side arm plates broad, in contact 

 distally. Arm-spine ridge prominent, bearing 7 long, slender, tapering 

 arm spines, the uppermost longest, more than 2 arm segments in length, 

 gradually reducing in length to the lowermost, which is shortest. 



Oral shields triangular, acute inner angle and rounded outer angles 

 with conspicuous granules on the distal margin, like those of the disk. 

 Adoral plates broad and narrow, slightly enlarged distally, meeting fully 

 within. Jaws long and narrow, bearing medially a pair of granules about 

 the size of those on the disk. Five to 7 oral papillae on a side. Outermost 



