Farquhar. — Two New Echinoderms. 213 



Eurygonias gen. nov. 



Odontasteridae with one conspicuous, recurved, hyaline, keel-shaped median 

 spine on the suture of each pair of mouth-plates ; the form is pentagonal ; 

 the marginal plates are few, large, and prominent, increasing in size 

 towards the apex of the rays, with one unpaired plate in both series on 

 the medial interradial line ; the abactinal intermediate plates are large, 

 angular, forming a meshwork, arranged in longitudinal rows, and bearing 

 large paxillae crowned with spinelets ; the actinal intermediate plates are 

 slightly imbricating, bearing groups of spines. 



Eurygonias hylacanthus sp. nov. 



The form is pentagonal with straight sides, much depressed, somewhat 

 inflated over the radial areas, with a distinct depression along the median 

 interradial line. 



R = 61 mm. ; r = 51 mm. ; R = l-2v, approximatelj''. 

 The supero-marginal plates are broader than long ; the one on the median 

 interradial line is triangular, with rounded angles ; the 6 plates on each 

 side of this one increase in size towards the apex of the ray, the last three 

 being very distinctly larger than the others. Outside of these there is 1 

 smaller plate and 2 or 3 very much smaller ones at the apex of the ray. 

 The marginal plates bear small, smooth, conical tubercles with minute 

 granular papilliform spinelets between them ; the outer part of each plate 

 is without the tubercles, but with a closely packed mass or papilliform 

 spinelets. 



The sides are bare, and the sutures between the plates broad and well 

 defined. The infero-marginal plates correspond in number, form, and 

 armature with the supero-marginals, the only difference being that the in- 

 crease in size of the plates towards the apex of the ray is somewhat more 

 marked than in the supero-marginals. The dorsal plates are irregular in 

 form, tumid, and angular, forming a distmct meshwork. They carry large 

 club-shaped paxillae. In the middle of the disc these paxillae are irregularly 

 placed. There is a single row along the median radial line, and parallel 

 rows to this on each side, with a few much smaller ones scattered here and 

 there between the rows. The largest are at the middle of the disc and along 

 the median radial line, and they decrease in size towards the edge of the 

 disc and towards the median interradial line, those on the edge of the 

 disc being very small indeed. The paxillae are covered at the top with 

 numerous granular papilliform spinelets, closely packed together, about 

 100 on the largest ones, forming large hemispherical knobs. The papular 

 areas have 3 or 4 pores each. 



The plates on the oral surface are irregular in form and size, pavement- 

 like, somewhat angular, tumid, and imbricating. They bear a closely 

 placed group of 7 or 8 rather long, cylindrical, granular, slightly tapering, 

 blunt spines, with a wreath of small granular spinelets at the base ; the 

 size of the spines decreases towards the edge of the disc. There is 1 

 large, stout, keel-shaped, hyaline spine on each pair of oral plates, with 3 

 or 4 small, somewhat flattened, slightly tapering spines at the apex of the 

 mouth-angle, a row along the edge on each side, and 2 or 3 larger ones 

 between this row and the large median spine. The specimen is dry, and the 

 adambulacral armature a good deal displaced, but it evidently consists 

 of 4 or 5 rows of rather long, cylindrical, blunt spines ; some of them taper 

 somewhat, while others are flattened and chisel-shaped. The madrepori- 



