148 NATURAL HISTORY BULLETIN 



Pectinaster dispar Verrill, sp. nov. 



Plate xiv; figures 1, la, 16. Details. 



The superomarginals are large and wide, encroaching on the 

 paxillary area, thus forming a wide and thick border. They 

 have wide and deep, fasciolated, oblique, sutural grooves. Each 

 bears one large spine of moderate length, about equal in length 

 to one and a half times that of the plate. The breadth of the 

 plate is more than half that of the radial paxillary area prox- 

 imally. 



The paxilliform plates are mostly small, stellate, spinose pro- 

 topaxillae. They bear six to eight long and acute marginal spin- 

 ules, and a longer central, erect, acute spine. Their radiating 

 spinules are longer, fewer and more spine-like than in any of 

 our other species. The papular pores form a small, central, 

 transverse group, with about four larger pores on each side of 

 the central one, without specialized plates. 



The inferomarginal plates are large and broad and have their 

 lower surface closely covered with rather large, short, stout, 

 acute, conical spinules, that are appressed and almost imbricated 

 in about six alternating rows. They are stouter and more con- 

 ical than in any of the other species, but not so long as in C. 

 ecJiinulatics. They increase in size and length outwardly. These 

 are followed by three or four larger, unequal secondary spines 

 around the base of the large, stout, marginal one. Some of the 

 secondaries are more than half as long as the large one. The 

 grooves between the plates are fasciolated with slender inter- 

 locking spinules. 



The adambulacral plates are large and prominent. The mar- 

 ginal edge bears a row of ten to twelve, or more, long slender 

 graded spines. The rows are continued all around the margin 

 of the plate by ten to twelve smaller and more slender spines. 

 The actinal face bears two larger and veiy unequal spines. The 

 larger one is very stout, conical, acute, not very long. The other 

 is very slender, equally long, tapered, acute. 



The type was from an Albatross station, locality unknown, 

 (No. 18,468, Nat. Mus.) 



