551 



the presence of numerous inferomarginaland usually 1 or 2 actinal 

 interradial pedicellariae; in the typical]}- somewhat larger disk. 

 E, 168 mm; r 22 mm; R 7,6 r; breadth of ray at base 26 mm. 



Acantharchaster iiiterniediiis new species. 



Differs from A. aciculosus in the absence of long accessory abactinal 

 spinules; in the restriction of papulae to disk and proximal seventh of 

 ray; in having stouter dorsolateral muscle bands; and in the smaller 

 mouth plates with comparatively few marginal spinules. R 158 mm: 

 r 17 mm; E, 8,3 r; breadth of ray at base 21 mm. 



Monterey Bay, California 958—755 fathoms. Bottom, mud. 



Cheiraster agassixi evoplus new subspecies. 



Differing from Ch. agassixi Ludwig in having abactinal and inter- 

 marginal pedicellariae and usually larger papular areas with more nume- 

 rous papular pores. Rays 5; R 72 mm; r 11,5 mm; R 6,4 r. Nearly 

 related to Ch. forcipatus (Sladen) and Ch. mirnicus (Sladen). From the 

 former evoplus differs in having larger papularia and differently formed 

 abactinal pedicellariae (pectinate in evoplus). In forcipatus the paxillae 

 have stouter spinelets and the central spinelet is short and conical; 

 secondary superomarginal spinule in evoplus .^ none in forcipatus; more 

 numerous and prominent secondary spinules on proximal inferomarginal 

 plates in evoplus^ and the furrow spinelets longer, slenderer, and curved. 

 Evoplus differs from miniicus by the presence in the adult and moderately 

 young specimens of abactinal, intermarginal, and much more abundant 

 actinal pedicellariae. The papularia are larger and contain many more 

 pores. In Ch. evoplus the furrow spinelets are slenderer and curved, 

 and the spine in the actinal surface of each adambulacral plate is not 

 so prominent as in inimicus, while the proximal inferomarginals are 

 more heavily armed than in nvimicus. 



Off San Diego, Cal., 1059 fathoms. Bottom, green mud. 



Goiiiasteridae. 



Pseudarchaster dis.sonus new species. 



Closely related to Ps. pectinifer Ludwig but differs in having actinal 

 bivalved pedicellariae of a highly characteristic form, coarser granules 

 to abactinal paxillae and superomarginal plates, proximally smaller 

 adambulacral plates, fewer actinal adambulacral spinelets and pointed 

 furrow spines. R 170 mm; r 61 mm; R 2,6 r. 



This species is characterized by post-ambulacral fascioles of a 

 bilvalved form, in reality pedicellariae, which may consist of multiple 

 opposing jaws. The actinal intermediate plates and their pedicellariae 



