194 A. JE. Verrill — Bevision Genera and Species of Starfishes. 

 Pseudarchaster ordinatus Ver., sp. nov. 



Plate XXX. Figures 4, 4a, 46. " 



A large species, having a broad disk, with the sides regularly- 

 incurved, and rather long, tapered, subacute rays, closely resembling 

 P. co7icinnus in form and in the character of the upper side, but 

 more, spinose below. 



Radii about as 1:2.8. Greater radius, 47 to 50'"°'; lesser, 

 17-18°"".. 



The abactinal paxillae are regularly arranged, and evenly granu- 

 lated, with very small, crowded, slightly elongated, round granules, 

 of which twenty to thirty may occupy the central part ; those around 

 the margin are longer and divergent. 



Upper marginal plates about 64 on each side of the body, much 

 higher than long, encroaching considerably on the disk, sloping 

 upward so as to form a bevelled margin. They are rather closely 

 and finely granulated, like the abactinal plates. They have the 

 narrow sutural grooves fasciolated. 



Lower marginals similar to the upper in size and shape, but cov- 

 ered with small, acute, unequal spinules, and with one or two median 

 vertical rows of larger appi-essed spines, of which there may be 8 to 

 10 or more on the larger plates. 



The actinal plates mostly have a long, rather slender, acute central 

 spine, surrounded by several small acute, erect spines. Many of 

 those of the principal series have pectinate fascioles between them. 

 Sometimes as many as 16 of these special fascioles occur on each 

 interradial area. 



The adambulacral plates bear a palmate furrow-series of seven or 

 eight slender, divergent, nearly equal spines ; one or two larger 

 central spines on the actinal side ; and an outer marginal curved 

 row of several small acute spinules. 



The jaws usually have an odd apical spine considerably larger 

 than the rest, but it may be lacking on some jaws; there are about 

 eight or nine spines in the furrow series, rather longer and larger 

 than those farther out ; and about seven to nine rather larger and 

 longer actinal spines on each dentary plate, so that the jaws appear 

 very spinose. 



The genital pores are small but easily visible ; they are situated 

 opposite to the second pairs of dorsal marginal plates. 



Taken by the Albatross in the Gulf of Mexico, at station 2396, in 

 335 fathoms (No. 18,438) ; also at station 2376, in 324 fathoms. 



