ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATERS FISHER 



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Adambulacral plates longer than high and on the basal portion of ray about as 

 wide as long. The armature consists of, on the aboral margin of the plate, a trans- 

 verse series of three spinelets and one spine (the subambulacral), or beyond the middle 

 of genital region two spinelets and one spine. At the base of the ray the two inner 

 spinelets are subequal-and the third longer, or the innermost is slightly shorter than 

 its plate, the second subequal to the plate in length, and the third about 1.5 plates in 

 length. The subambulacral spine is 10 to 1 1 mm. long or 4.5 to 5 plates. On plates 

 which have a lateral plate and spine on their outer side, the subambulacral is shorter 

 than on alternate plates with no lateral spine. The first 12 to 15 subambulacral 

 spines have a flaring, circular, truncate tip beset with numerous little points as in 

 Craterobrisinga. The sixth to ninth spines have the broadest tips. On the distal 

 attenuate portion of the ray there is one furrow spinelet and one subambulacral, two 

 to the plate, as over most of the ray of the immature example. First adambulacral 

 plate joined to its fellow of adjacent ray, and proximal ends of the second plates 

 touching one another. 



Actinostome rather wide, 16 mm. in diameter. Mouth plates small, incon- 

 spicuous, rather narrow, with a flaring inner or free margin, the combined pair being 

 shield-shaped. Armature consists of three or four membrane-invested pedicellanae 

 bearing spinelets on the inner, free, flangelike margin of the plate, that nearest the 

 median suture the shortest, the rest evenly graduated in size outward. At the aboral 

 end of the plate are one or two similar spinelets reaching nearly across furrow. On 

 the actinal surface two much heavier and larger, pointed, sacculate spinules stand in a 

 longitudinal series, the inner the longer, and slightly nearer the median suture. 

 Sometimes there is only one spine, or as many as three. 



Madreporic body small, sub tubercular, situated near margin of raised portion ot 

 disk. Its borders are beset with numerous spinelets. 



The articulating surface of the ambulacral plates, on the border of disk where a 

 ray has been broken off, is small, about 2.25 mm. high, and oval in form, slightly 

 broader above than below. . 



Color in life: Abactinal surface of disk flame scarlet; rays salmon pink with a 

 yellowish cast, much lighter than disk; edges of furrow pinker; spines salmon pink; 



tube-feet pinkish orange. 



Immature specimen.-An example having R 99 mm. has the full number of rays. 

 The genital region extends a little less than one-third the total length of ray. The 

 prickles of the middorsal area are less compactly placed, and-the plates are even 

 thinner than in the adult. On the first eight or nine adambulacral plates there are 

 two aboral spinelets and the large spine; beyond that point only one furrow spinelet 

 and the subambulacral. The proximal subambulacral spines are not much enlarged 

 at the tip and only the first four or five are modified. The mouth plates have only 

 one suboral to each plate, and there are two actinostomial spinelets, the outer at the 

 entrance of the ambulacral furrow, the inner immediately adjacent to the outer 

 spinelet and slightly spaced from the median suture 



Anatomkal notes.-Theve are along each side of the ray 20 to 23 mature gonads 

 in the form of independent globular sacs, 2 to 3 mm. in diameter, attached to a genital 

 stolon Beyond these are about 20 immature, often very small, gonads, which extend 

 beyond the end of the long genital region, or a distance equal to about five times the 



