166 NATUEAL HISTOEY BULLETIN 



species. Hence there is considerable confusion as to the names. 



Perrier stated (1876) that he had examined the types of Gray 

 and of Miiller and Troschel, and a cotype, sent by Liitken, of 

 his variabilis, and had found them all identical. Therefore the 

 name given by Gray must he adopted. But Perrier gave no de- 

 scription of the species, except a translation of part of that of 

 Miiller and Troschel. 



Special description : A well-grown specimen, before me, seems 

 to be the fully developed and normal form of this species. It is 

 from the Albatross station 2407; N. lat. 28° 47' 30'', off W. 

 Florida, in 24 fathoms. (No. 10989, Nat. Mus.) 



The radii are 14°^°^ and 74^°^ ; ratio, 1 :5.3 ; breadth of rays at 

 2d marginal plate, without spines, 15™°" ; radius of disk is equal 

 to the radial length of five and a half basal marginal plates. 

 Superomarginal plates are large and high; 25 on each radial 

 margin. 



The rays are angular, regularly tapered to narrow tips, high 

 on the sides at base. The inferomgrginal plates project, on the 

 sides of the rays, beyond the upper ones, forming, with the lower 

 ends of the latter, a lateral fasciolated furrow, covered with fine 

 spinules. 



The superomarginal plates are thick vertically with the outer 

 side rising rather steeply, and the top, especially the first two 

 pairs, prominent above the paxillar area. On the first seven 

 plates there is a short, stout, tapered, acute spine, seated on the 

 top of the plate and thus forming a short inner row. These 

 spines are larger on the first two plates, decreasing to small short 

 spines on the seventh. 



An outer series of similar spines commences on the third plate 

 and extends to the end of the ray, decreasing regularly. The 

 surface of the plates is closely covered with short rounded gran- 

 ules, larger around the base of the spine, and grading into fine, 

 short, crowded spinules in the fasciolated grooves, which are 

 narrow and beyond the middle of the rays, distinctly oblique. 



The inferomarginal plates bear two, or often three, rather 

 short, flattened, subacute or acuminate spines ; on the lower side 

 there is along each margin a row of three or four unequal, flat, 

 somewhat appressed spines, and between them the surface is cov- 

 ered thickly with rather coarse, elongated, somewhat flat and 



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