108 BRISINGIDAE. 



adambulacral plates. Inferomarginal plates very small and difficult to detect; 

 apparently only every alternate plate carries a spine but proximally this alter- 

 nation is not perfect as there two successive plates may be spine-bearing. 

 Adambulacral armature consisting of a single spine; on no plate is there any 

 indication of a furrow-spine or of a point to which it might have been attached. 

 Both inferomarginal and adambulacral spines are for the most part missing or 

 when present are broken, but to judge from the fragments distally the infero- 

 marginals were the larger and both series were encased is thick skin. Infero- 

 marginal tubercles are placed directly above adambulacral tubercles but only 

 adjoining every other adambulacral plate. Tube-feet of moderate size arranged 

 in pairs opposite the distal half of the adambulacral plates; pores about one 

 millimeter in diameter. Genital glands moderately developed, one on each 

 side of swollen area. 



Station 4651. Peru: west of Aguja Point, 111 miles, 2,222 fms. Bott. temp. 35.4°. Fne. stky. gy. m. 



Two rays. 



Comparison of these rays with Fisher's figures and description of Brisinga 

 fragilis (1906. Bull. U. S. Fish Comm., p. 1115, plate 46, fig. 1, plate 48, 

 fig. 3, 3a-c), the genotype of Brisingella, has left no doubt in my mind that they 

 too represent a species of this genus, and one which is apparently unique in its 

 adambulacral armatvue. As the uniform absence of a furrow-spine at either 

 end of the adambulacral plate and the equally uniform occurrence of only a 

 single actinal spine on the same plates and that aboral, make the recognition 

 of the species easy, it seems proper to give it a name. 



Freyellidea brevispina,' sp. nov. 

 Plate 5, fig. 1, 2. 



Rays 11. Disk 12 mm. across. R = 165 mm. or more. R = about 14d. 

 Disk circular with nearly vertical sides between the rays, densely beset with 

 spinelets, .50-.75 mm. long; these spinelets are slender, sUghtly thickened at 

 tip where they terminate in two, three, or four short points; occasionally the tip 

 is blunt; the plates bearing these spinelets are difficult to make out but appar- 

 ently there is only one spinelet to a plate ; pedicellariae of diverse but small size 

 occur not rarely among the spinelets. Madreporite small but elevated and 

 prominent on the margin of disk. Rays slender, only a little over 2 mm. wide 



1 brevispinus = having short spines, in reference to the unusual oral spines. 



