ASTEROIDEA OF NORTH PACIFIC AND AD.IACKNT WATERS FISHKIt. 263 



fuiTiiw spines, or iiioro taj)oro(l and loss conspicuously fcroovcil. The inner or fnrmw 

 spines A-ary in the extent and depth of the <;roove. 



Mouth plates with ahout four marginal spines (rarely live) decreasiiifj in lfn>;tli 

 toward the first adamhuhural, the inner or largest heing about the same size us a 

 furrow spine and all similarly grooved; one spine on the actinal surface of plate of 

 same size as corresponding adambulacral spines. 



Anal opening surrounded by numerous slender papilliform spinelets. 



Madreporic body situated at about middle of miiioi- radius, prominent, with 

 more or less sinuous centrifugal striations. 



Color in life, general tint cream color, abactinal surface lighter, but apical area 

 bufT yellow. In some specimens huffy spots are scattered here and there over 

 surface of body. 



Anatomical notes. — Stomach spacious; hepatic or radial coeca large, reaching 

 nearly to end of ray; intestinal coeca large, with numerous small lobes, forming a 

 mass not unlike an ovary in appearance. In the example dissectoil there are 

 eight or nine of these diverticula lying over the hepatic coeca. Centrally they open 

 into a rather spacious chamber separated fnmi the stomach by a small orifice; 

 dorsally the chamber t)pens by the anus; the diverticula are about one-third or 

 one-fourth R in length. Retractors of stomach large and strong. One Polian 

 vesicle in each interradius, except that of the matlreporic canal: canal slender, 

 sinuous, with easily distinguishable rings of calcareous matter in its walls, reminding 

 one of the trachea o{ a bird ; tube feet with strong sucking tlisks, and single ampullse 

 (not two-parted or divided as described by Ludwig in Alexamlraster mirus; this is 

 a mistake, I think). The ampullre are rather large and form a double series along 

 either side of the ambulacral ridge, but there is only a single ampulla to each orifice; 

 possibly this double series gave the erroneous impression that the ampulla? are 

 double in Alexandraster mirus. Interradial septa membranous, the gonads being 

 attached to the dorsal surface on either side of it, and in the interradial angle. 

 First ambulacral ossicle forked at bottom and heavier than the succeeding ones. 



Variations. — This is a variable species in respect to the length, number, and 

 shar})uess of the abactinal and lateral spines, those of the type being stouter and less 

 numerous than in others from Monterey Bay and San Diego, California. At the 

 same time there are specimens from the latter locality which are nearly or quite 

 typical and match examples from Monterey Bay. The type has the grooving of 

 the adambulacral and actinal spines more pronounced than in some other speci- 

 mens from botli Monterey Bay and off San Diego. In these tlie spines are slenderer 

 and the groove instead of running to the base runs only part way down the spine, 

 or is restricted to the tip, and the depth of the groove varies, being very shallow 

 in a few examples. In the type the two adambulacral spines are about ecjual in 

 length, near the base of ray, the inner shorter distally. More than half of the 

 spe<imcns have the inner considerably shorter all along the furrow: as, for instance, 

 a large specimen from station 4370 has outer spine 5.50 mm. and corresponding fur- 

 row spine 4.25 mm. The thickness of the skin is slightly variable, and some exam- 

 ples have the rays more inflated and rigid than others. Certain other variatioua 

 have been coosidered in tlie descriplinn and need not be repoateil. 



