STARFISHES OF THE PHILIPPINE SEAS. 123 



I 



Type-locality. — Station 5301, China Sea, vicinity of Hongkong 

 (lat. 20° 37' N.; long. 115° 43' E.), 208 fathoms, gray mud, sand, 

 bottom temperature 50.5° F. ; 1 specimen. 



Distribution. — China Sea. vicinity of Hongkong. 



SpeclTnens examined. — The type, and 1 specimen from station 

 5302, near type-locality 38 fathoms, soft gray mud (probable error 

 in localit.y). 



Remarks. — This species differs from luzonicus in having still nar- 

 rower rays; superomarginals which encroach less upon the paxillar 

 area, and which have proportionately higher lateral faces; more 

 delicate superomarginal spinelets; practically no specialized spines, 

 except a very small one on the distal plates; actinally narrower in- 

 feromarginal plates with only 1 small actinal spine on a few proxi- 

 mal plates; shorter lateral spines; more restricted actinal interme- 

 diate plates; adambulacral pedicellariae ; proximally fewer subam- 

 bulacral spines; longer and slenderer terminal plate. The narrow 

 rays, narrow inferomarginals and superomarginals, shorter lateral 

 spines, and the short series of actinal intermediate plates are among 

 the differences separating tenuis from eiiryactis and anchistus. 

 From muUicinctus, tenuis differs in not having such tumid marginal 

 plates, in having shorter lateral spines, no superomarginal spine, 

 fewer furrow spines, smaller paxillae, and a more pronounced angle 

 between the actinal and lateral faces of the inferomarginal plates. 

 In multicinctus the actinal surface of the plates is beveled and the 

 outer end quite tumid. An additional difference is the absence in 

 tenuis (and in the other preceding species) of the specialized abac- 

 tinal pedicellariae. These occupy low plates independent of the 

 paxillae. 



Psilaster gracilis Sladen seems to be an aberrant Persephonaster., 

 with much reduced marginals. It differs from Psilaster and agrees 

 with Persephonaster in having at the base of each tooth a group of 

 spinelets — a part of the marginal series — directed across the mouth 

 of the furrow. P. gracilis has even more attenuate rays than P. 

 tenuis, and has much smaller marginal plates. The inferomarginals 

 are narrow and rounded, without a prominent actinal face, and the 

 mouth plates are smaller, with a smaller tuft of spinelets at the 

 mouth of furrow. 



PERSEPHONASTER MULTICINCTUS Fisher. 



Plate 25, fig. 1; plate 26, fig. 1; plate 27, fig. 1; plate 37, figs. 2, 2a-c. 



Persephonaster multicinctus Fisher, 1913o, p. 616. 



Diagnosis. — Of the type of P. cingulatus Fisher and related to P. 

 roulei Koehler, from which it differs in having abactinal and mar- 

 ginal pedicellariae; fewer paxillar spinelets; a slender appressed, 



