56 Proceedings of the Biological Society of Washington. 



size and shape, but distally they are somewhat smaller. The upper 

 border of the inferomarginals imbricates sliglitly over the lower border 

 of the corresponding superomarginals. Each inferomarginal bears two 

 spines, which are similar to those borne by the snperomarginals. 



The actinal intermediate plates are two (rarely three) in number, 

 rounded, suspended in perisome just beyond the two tubercles on the 

 inner border of the odd interradial marginals, or just distal to the outer 

 angles of the mouth plates. 



The adambulacral plates are slightly longer than broad ; their distal 

 and proximal borders are parallel, oblique, slanting adorally toward the 

 furrow ; the furrow border forms a prominent angle with a rounded apex 

 and concave sides. The first adambulacral plate is separated from the 

 odd interradial inferomarginal by the actinal intermediate plate; the 

 second adjoins the first inferomarginal ; the third lies across the suture 

 between the first and second inferomarginals ; from this point onward 

 the adambulacrals, slightly more numerous than the inferomarginals, 

 sometimes correspond, sometimes alternate, with them. The armature 

 consists of two, rarely three, small slender spines situated side by side at 

 the apex of the angle on the extreme inner edge well within the furrow ; 

 behind these, on the inner edge of the plate as viewed actinally, a much 

 larger spine, resembling those on the inferomarginals, though very 

 slightly smaller and less stout. 



The mouth plates bear three long spines along the furrow which de- 

 crease rapidly in size outwardly; on the actinal surface of the plates, 

 within the outermost of these, there is a single spine resembling the 

 longest of the furrow series. 



Color in alcohol dull gray, below white. 



Type.— C&t. No. 36,895, U. S. N. M., from "Albatross" Station 2992, 

 off Clarion Island, Lower California, in 460 fathoms. 



Family GONIASTERID^ Forbes. 



Subfamily Anthenein^ Fisher. 



Anthenea mexicana new species. 



Five arms; R=54 mm. ; r=24 mm. ; R: r=2.2o: 1 ; superomarginals 13 

 or 14. 



Form stellate, with the interbrachial arcs and the tips of the rays well 

 rounded. At the ends the arms are abruptly upturned so that the tips 

 stand vertically. 



The outline of the dorsal plates, which are flat and not tumid, is more 

 or less concealed. These plates bear distinct, usually cylindrical, tuber- 

 cles, which are arranged in regular rows parallel to the mid-radial line 

 of the arms. The most prominent of these tubercles are in two rows, 

 one on either side of the mid- radial line, about 3 mm. apart at the widest 

 point, which run from a point half way between the center of the disk 

 and the arm base almost to the arm tip ; the slightly sunken naked area 

 between these rows (occupying the mid-radial line of the arm) decreases 

 very slightly in width toward the arm tip. Beyond these rows on either 



