256 Yen' til, Notes on Jladiata. 



This species is very diiferent from the others of this region, but 

 reserahles O. voriegata most. The latter has, however, much longer 

 ai-m-spines, of which the upper are longest ; much longer arms ; 

 smaller under arm-plates, which are more hexagonal, scarcely broader 

 than long and convex outwardly ; the mouth shields are more rounded) 

 broad oval, more pi'ominent, and less acvite inwardly; the mouth- 

 papillae are different in form, the outermost one being shorter and 

 stouter and not overlapping the next ; the upper ovarial openings are 

 slits near the base of the arms, beneath, not visible from above. The 

 color also is quite different. 



The peculiarity in the form and position of the upper genital open- 

 ings may hereafter require this species to be separated generically 

 from Ophiura, if accompanied by corresjionding internal differences 

 in structure. 



Ophiolepis variegata Liitken, Vidensk. Meddelelser, Mar(-h, 1856; Addit., p.l06. 



Mr. Bradley has sent specimens of this species, dredged at 

 Panama, of various sizes. From La Union he sent quite a number 

 of very large ones, which came, however, in a badly broken con- 

 dition. At the latter locality it appears to be abundant, in 6 or 7 

 fathoms, muddy bottom. 



Dr. Lutken's specimen was quite young, agreeing well with some of 

 our smallest ones. The adult specimens present somewhat different 

 characters. It is closely allied to 0. elegans Liitk. of the West Indies. 



The largest specimen from Panama has arms 1*8 inches long; disk 

 '6 in diameter. The mouth-papilhie, eleven to each angle of the mouth, 

 resemble those of O. elegans. The outer one on each side is longer 

 and sharper than the rest, quite overlapping the next one, which, like 

 the succeeding three, is short and broad, with a cutting edge. The 

 mouth-shields are more than twice longer than broad, the outer end 

 rounded ; the sides reenteringly curved ; the inner edge pointed, with 

 nearly straight sides. Side mouth-shields large, quadrangular, the 

 inner sides longest, slightly concave ; the inner lateral sides in con- 

 tact along their whole extent, the outer edge in contact, for three- 

 fourths its length, with the mouth shield, the outer corner projecting 

 into the genital slit ; the outer lateral edge is a little concave, exceed- 

 ing the inner lateral and about equal to the outer edge. Under arm- 

 plates, toward base of arms, twice broader than long, the outer edge 

 concave, the inner convex, the sides strongly concave; along the 

 middle of the arms they are more nearly square ; toward the end 

 of the arms they become longer than broad, with a convex outer 

 edge, concave sides and nearly pointed inner edge. Upper arm- 

 plates broader than long, toward base of arms, the outer and inner 



