270 J^^W STARFISHES AND OPHIURANS—VERRILL. 



covered with short, thick, bhint, almost gramile-like spinules and with 

 a great abundance of comparatively large crossed pedicellari.B, which 

 are also scattered over all the plates, both of the dorsal and lateral 

 surfaces of the arms and disk; many of these pedicellarine are nearly 

 as large as the adjacent spinules and about half as thick as the larger 

 spiuules of the dorsal series. The rows of plates along- the sides of the 

 arms are destitute of spinules, but are thickly covered with i^edicellarife. 

 Adjacent to the adambulacral i)lates there is a row of stout ventral 

 plates, each of which bears two stout, obtuse, club-shaped s^iines placed 

 side by side and forming a somewhat irregular row, which terminates 

 before reaching the middle of the arm. Outside of these there is another 

 row of prominent plates, each of which bears one or two small spines 

 toward the base of the arms, but beyond the middle of the arm each 

 bears two spines or sometimes three, like those of the inner row. The 

 surface of these large ventral plates is covered, like the dorsal aud lateral 

 ones, with large crossed pedicellarite. Each adambulacral plate bears 

 two or sometimes three moderately long, round, blunt, and often 

 slightly clavate spines, so arranged as to form two pretty regular rows. 

 Near the mouth each plate usually bears a single spine forming a 

 simple row. Attached to the adambulacral spines and in the ventral 

 interradial spaces are many acute, ovate, forcipate pedicellariae, often 

 mixed with crossed i)edicellariie and scarcely exceeding the latter 

 in size; along the inner edge of the adambulacral furrow there are 

 numerous smaller pedicellaria' similar in shape. Many of these are 

 raised on slender pedicles; they ofteu form a group of three or four on 

 the inner end of each plate. Jaws elongated, with three or four rather 

 long, round, subacute spines in a row along each side, and with four 

 longer convergent spines at the inner end, two of which are directed 

 upward and inward. 



The central part of the disk is covered by a system of rather large 

 X)rimary plates, which form a more or less distinct rosette. The mad- 

 reporic plate is near the center, moderately large, tlattish or somewhat 

 concave, and surrounded by numerous spinules like those of the neigh- 

 boring plates. It occupies tlie whole upper surface of a large primary 

 basal plate. The plates of the median dorsal series are rather large 

 and prominent, closely united in a continuous series; their prominent 

 crests are transverse and bear about 10 to 12 spinules, which are 

 arranged in about two irregular transverse rows, intermingled with the 

 pedicellarife; another row of similar but somewhat smaller plates 

 extends from the dorsal interradial angle to the tip of the arm on each 

 side; this row, at lirst dorsal, becomes median-lateral at about the 

 middle of the ray. Toward the base of the arm these plates usually bear 

 a transverse row of 2 to 4 small spinules on a distinct crest or 

 ridge, but these mostly disappear before reaching the middle of the 

 arm; between this row of i)lates aud the median dorsal row on the 

 basal part of the arm tlierc is an intermediate low of smaller plates, 



