JAPANESE ASTEROIDEA. 319 



tip of ray ; four to sis, or even more, occur around each plate, according to 

 its size and shape. 



" Variations. — The examination of seventy specimens of this species, 

 inchiding one from off Misaki, Japan, 640 melters, kindly sent by Dr. 

 Seitaeo Goto, of Tokio, reveals a considerable range of individual variation. 

 The differences which the American specimens seem to present are greatly 

 overshadowed by individual differences occm'ring in examples from the same 

 station. Sladen apparently had only one specimen, and of com'se could 

 give no hint of this variation in Ms excellent description. 



" General form, etc. — Some specimens are more arcuately pentagonal 

 than Sladen's figm'e and of the same form as his figure of patagonicus. 

 The Misaki specimen is about intermediate in form. The Washington 

 specimens are less arcuate than many of those from Bering Sea. The abac- 

 tinal area varies in the amount of inflation, and corresponding to this the 

 interradial sulcus is more or less evident. There is one four-rayed example. 



" Ahadinal plates. — Two large specimens from stations 3330 and 3331, 

 Bering Sea, in practically the same locality exhibit very nearly the extremes 

 of variation in the size of plates (PI. 37, figs. 1 and 2). That from station 

 3330, specimen A (fig. 2} has E=92 mm., while B has R=91 mm. In A 

 the largest tabula of the median radial region are 3 mm. in diameter, in B 

 3.5 mm., but in A there are relatively much fewer large tabula and the 

 spaces between them are much wider than in B, as will be seen from the 

 photographs. This difference in the size of the tabula and in the extent of 

 space between is duplicated in other localities. The larger tabula have 

 larger granules, not a correspondingly greater number ; eighteen to twenty- 

 fom- marginal gi-anules, and eighteen to thirty in the central group is the 

 range in large specimens. In dried specimens the marginal granules are 

 concave on the top, the others are flat. Pedicellarise are usually very 

 numerous, occurring on a majority of plates of the papular areas. 



" 3Iarginal plates. — The greatest variation of all is in respect to the 

 marginal plates. Typically these form a tumid rounded border, but excep- 

 tionally are nearly as thin as in leptoceramus. Again, the two specimens 

 .mentioned above will serve to illustrate the extremes of size. In A, which 



