258 



BULLETIN 76, UNITED STATES NATIONAL MUSEUM. 



widely than does miniata, judgin<^ by t'le specimens in the Stanfortl University 

 collection. The principal dilTcrencPs are as follows, lar<,'e specimens being used for 



comparison : 



pectinifrra. 



General form stellato-pentagonal, to pentagonal 

 with nearly straight sides (Mororan, Hokkaido); 

 R=1.4r to 1.5 r. 



Papular areas small ; less than fifteen papulje on 

 proximal radial regions. 



Primary abactinal plates more closely placed 

 with fewer (five to fifteen) and relatively larger 

 secondary plates on the papular areas of proximal 

 radial region. 



Carinal series of abactinal plates and their gran- 

 ules not conspicuously larger than adradials, and 

 not forming a noticeable series (viewed internally 

 they do, however). 



The primary groups of abactinal granules only 

 exceptionally of the wide crescent form (then disk 

 is pentagonal) but generally more elliptical, or 

 bowed elliptical, with fewer granules (about twelve 

 to twenty on proximal carinals). 



Spinelets of actinal combs not longer than base 

 line of comb of four. Difference in size of actinal 

 spinelets in the two species more evident on com- 

 parison of specimens. Usually five or four, " rarely 

 three spinelets to a comb. 



Serrate scars with fine teeth or bas-relief serra- 

 tions. 



Frequently four furrow and four or five" actinal 

 adambulacral spinelets; longest actinal and furrow 

 spinelets less than two adambulacral plates with 



General form stellate with broad rays and curved 

 interbraehial arcs; R=1.7 to 2 r. 



Papuhu- -Axcis large, with about fifteen to twenty 

 pores on proximal radial regions. 



Primary abactin.al plates rather well spaced with 

 fifteen to twenty-five secondary plates on the in- 

 tervening meshes of proximal radial region. 



Medioradial (carinal) series of abactinal plates 

 and armature usually fairly regular and conspicu- 

 ous proximally, the crescents being much larger 

 than adradial series. 



Primary groups of abactinal granules of a wide, 

 crescent form, except toward margins, and with 

 many granules (abont forty on proximal carinals). 



Spinelets of actinal combs longer than the base 

 line of a comb of four spinelets (much longer than 

 one of three); usually three or four spinelets to a 

 comb. 



Serrate scars on actinal plates larger (difference 

 apparent on comparison). 



Three furrow and two or three actinal adambu- 

 lacral spinelets; longest furrow and actinal spine- 

 lets equal to or exceeding two adambulacral plates 

 with suture. 



Family ECHINASTERID.5: Vcnill, restricted. 



EchinasUridse Verrill, Trans. Conn. Acad., vol. 1, pt. 2, 1867, p. 343.— Perkier, 1875, 1884, 

 1894.— ViGUlER, 1878.— Sladen, Challenger, Asteroidea, 1889, p. 535. 



Spimdosa with a reticulate, more or less irregular skeleton formed of small 

 imbricating plates bearing isolated or grouped spines; with biserial tube feet and 

 single ampullar; suckers of tube feet without rosette of calcareous reticulum; no 

 pedicellariae. Interbraehial septa weak, more or less rudimentary. 



Remarks. — This family, as originally- established b}- Vemll, comprised the 

 genera Echinaiiter, Acanthaster, Alithrodia, and Ferdina. Perrier subsequently (1875) 

 added Solaster, Ilenricia, and Valvaster, and placed Ferdina in the LinckiidiP. Yiguier 

 di^•ided the family, in 1S78, into four tribes, the Echinasteriuje, ilithrodiina^, Valvas- 

 tcrinffi, and Solasterinse. In 1S84 Perrier cstabhshed the family SolasteridiB for 

 Solaster and placed Mitfirodia in a distinct family, which, however, he called ' 'Mithro- 

 dinse." Sladen, 1S80, maintained the family Solasteridre, and jilaced Mitlirodia 



"These numbers refer to specimens 40 mm. or more major radius. 



