28 BULLETIN 76, UNITED STATES NATIONAL MUSEUM 



equals 5 plates in length. It is covered with a sheath closely beset with minute 

 pedicellariae. 



Adambulacral plates rather slender, longer than broad. Armature consists of 

 two furrow spinelets at the aboral end of the plate, on the distal apophysis, the prox- 

 imal spinelet usually a little the longer and about equal to the length of the plate 

 measured on the actinal surface. A little aboral to the middle of the plate is the 

 subambulacral spine which on the first nine plates has a broadened two or three 

 pronged tip. These modified spines are about two adambulacral plates in length, 

 while the sharp ones are a trifle longer. A few plates have a second shorter subam- 

 bulacral near the first but it is not normal. On the distal attenuate portion of the 

 ray where the ambulacral furrow is very narrow, the furrow spinelets are lacking. 

 Both subambulacral and furrow spines are liberally supplied with pedicellariae, those 

 on the furrow and proximal half of the subambulacral are conspicuously larger than 

 the pedicellariae of the lateral spines and distal half of the subambulacral spines. 

 Ludwig states that the adambulacral plates of his specimen of insignis have a single 

 furrow spinelet. I have a specimen from station 3381, Gulf of Panama, one of the 

 four which he lists, in which a considerable number of the plates have two aboral 

 furrow spinelets. 



Mouth plates small, with wide median suture, and very little modified from a 

 pair of adambulacral plates. Armature consists of two spinelets on actinostomial- 

 furrow corner of the plate (sometimes three) and one spinelet on the distal furrow 

 corner, all provided with good-sized pedicellariae. There is a single slender, blunt 

 suboral spine about two adambulacral plates in length. 



The apex of the interbrachial angle nearly touches the mouth plates, and is 

 bounded by the first adambulacral plates, above which there are no prominent 

 marginal plates as in Freyellaster. The proximal ends of the first pair of adambulacral 

 plates in each interbrachium touch, but the plates are not joined by their lateral 

 faces as in Freyellaster. 



Types. — In U. S. National Museum. 



Type-locality. — Gulf of Panama. 



Distribution.— Gulf of Panama to southern California; 1,772 to 2,228 fathoms 

 on gray mud, green mud, brown mud, and globigerina ooze; temperature range. 

 35° to 36° F. 



Specimens examined.— Station 4397, off Santa Catalina Island, Calif. (33° 10' 

 15" N., 121° 42' 15" W.); 2,196 to 2,228 fathoms, gray mud; bottom temperature, 

 35° F.; one specimen. 



Station 3381, Gulf of Panama; 1,772 fathoms, green mud; bottom temperature, 

 35.8° F.; one specimen. 



Remarks.— The single Californian specimen is small and presents slight differences 

 from the typical form from off Panama. There are regularly two aboral furrow 

 spinelets, instead of usually one (occasionally two), and the disk spinelets are not so 

 densely placed, nor are there so many spinelets on the abactinal arm plates. But 

 the California specimen is immature, which would account for the fewer disk spinelets 

 and fewer spinelets on the abactinal plates of the ray. It is not possible to determine 

 whether this specimen represents a distinct northern race. It lives in somewhat 

 deeper water than the southern form. 



