ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATERS — FISHER 99 



even deeper water (229-291 fathoms) matches Monterey Bay specimens from 56 

 fathoms. The first specimen (4410) has numerous very large straight pedicellariao 

 while the second has very few. 



No specimens from the southern part of the range are so large as the three from 

 Naha Bay, Kell Bay, and Port Chester (pi. 51, fig. 1), although from station 4553, 

 Monterey Bay, is a typical specimen with R 240 mm. The Kell Bay example has 

 R 280 to 290 mm. The type of Yerrill'sf or cipulata has a ray 325 mm. long. (Depar- 

 ture Bay, 18 fathoms.) This last form is simply a giant/orren, typical in all respects. 



Anatomical notes. — The skeleton of the adult (pi. 44, fig. 1) if a little more regular 

 would consist of a series of triangular meshes adjacent to carinals (point, outward) 

 another adjacent to superomarginals (point, mesad) and separating these two, a 

 series of quadrilateral or lozenge-shaped meshes. The actual approximation to this 

 ideal can be observed in the figure, from which the rudimentary actinals and the 

 adambulacrals have been omitted. Although the open dorsolateral skeleton suggests 

 Coronaster, the resemblance is entirely superficial. Coronaster has very large, square 

 intermarginal meshes with secondary ossicles connecting the superomarginals to 

 inferomarginals. 



A characteristic feature of the skeleton is the presence of secondary supcro- 

 marginal and carinal plates between the lobed primary plates. These begin to 

 develop in very small specimens (pi. 44, figs. 2, 3), and in fully grown examples there 

 may be two or three between two carinals but generally only one between the 

 superomarginals. 



The ambulacral plates are less crowded (and hence less compressed) than is 

 usual in the Asteriidae. Thus in a space of 10 mm. at the base of ray there are 10 

 ambulacral plates in the large Port Chester example, while in an equally largo Orth- 

 asterias koeMeri there are 14, and in Evasterias troschelii, 13. The ambulacral pores 

 are unusually large and the outer pore series is nearer to the inner than in Orthasterias. 



The small actinostome is surrounded by a massive ring of plates (pi. 45, fig. 5) 

 composed chiefly of conspicuous odontophores and the enlarged proximal end of the 

 ambulacral ridge. In Figure 56 is shown an unusual side view of the end of the 

 ambulacral ridge, with a single mouth plate attached, the mouth pair having been 

 separated at the median suture. The sutural face, as well as that of the first two 

 adambulacrals, is exposed. The odontophore abuts against the points x and xx, 

 acting as a keystone to that arc of the circle. (Fig. 5o). A dorsal process of the 

 mouth plate (M') also forms an essential part of the circle. 



The first spiniferous inferomarginal is really the second plate (pi. 44, fig. 2, 4, II) 

 of the series. The first plate is early shoved out of line and is under the second. 

 In small specimens (fig. 4) it would be mistaken for an actinal. The latter are later 

 developed between it and the adambulacrals. The small unpaired "actinal" plato 

 shown in Figure 4 (AC, fig. 2) forms a part of the interbrahcial septum and in old 

 specimens sinks under the integument. It is apparently not a true actinal plato. 



Viscera: There is a large three-parted intestinal coecum, the thin-walled lobes 

 of which extend into the base of three rays. Its dorsal surface is closely pressed 

 against the dorsal wall of the disk. The dorsal stomach is fairly well differentiated 

 from the ventral and the large hepatic coeca extend a little over two-thirds the length 

 of the ray. The stomach proper is eversiblo, very spacious, and fills the small disk, 

 its lobes extending into the rays a short distance. The gonads, undeveloped in the 

 specimen examined, lie wholly within the ray. Each consists of a central axis and 



