NO. 5 CLARK: ECHINI OF WARMER EASTERN PACIFIC 309 



the upper side. Ridges between pore-pairs of unpaired petal (except 

 adapically) with 7 or 8 tubercles rather close together; the miliary 

 tubercles on these ridges scarcely more numerous. Madreporite rather 

 small, about 3 mm across; ocular pores minute, but evident; genital pores 

 distinct but not very large. Unpaired petal nearly 40 mm long, and about 

 17 mm wide, the interporiferous area some 9 mm, where widest, near 

 middle; there are about 60 pore-pairs on each side and they nearly meet 

 at tip so the petal is virtually closed. Anterior petals rather more than 30 

 mm long, and 17 mm wide, elliptical rather than oval, and only very 

 slightly open at tip. Posterior petals, similar but longer (36 mm) and 

 wider (19 mm), scarcely more open at tip. Periproct about 5 mm across, 

 scarcely longer than wide, some 3 mm from the test margin, covered with 

 numerous miliary-bearing plates. 



Primary spines smooth and blunt, dorsally about 2 mm long but some- 

 what longer orally and near the mouth they may be 4 or 5 mm long. They 

 are blunt and seem fragile ; they may be slightly flattened or thickened at 

 tip but are not noticeably widened. Miliary spines as long as the primaries 

 and excessively slender ; with the larger spines they form a close dense coat 

 on the dorsal side ; orally they are less numerous and hence the covering 

 of the oral side is notably less dense than dorsally. Pedicellariae numerous 

 and large ; there is great diversity in the size but nearly all are tridentate 

 and none are characteristic. 



Color of the dry specimen is vinaceous to Hay's brown, aborally; 

 orally the vinaceous tint is more or less replaced by clay color. The oral 

 spines are clay color or lighter with the middle, and often most of the 

 distal half definitely dark vinaceous brown on the upper or outer side. 



The unique holotype of this Clypeaster was taken December 13, 1934, 

 at Station 347-35 off North Seymour Island, in the Galapagos Islands, on 

 a bottom of sand, rock and shell, in 3 fms. It was first referred to rotundus, 

 later to ochrus or speciosus, but the long, narrow and high test, the un- 

 usual coloring and the shape of the petals, preclude reference to any of 

 these known species. Among the scores of Clypeasters in the Hancock 

 collection this individual stands out unique. It seems best to give it a name, 

 even if additional specimens are never taken. 



Type. — Holotype, AHF no. 47. 



Type locality. — Station 347-35, off North Seymour Island, Galapagos 

 Islands, 3 fms, December 13, 1934. 



Distribution. — Type locality. 



Depth. — 3 fms. 



Specimens examined. — The type specimen only. 



