JAPANESE ASTEEOIDEA. 



637 



À. pcctwifcra seems to vary more widely than does mininto, judging hj the 

 specimens in the Stanford University collection. The principal differences 

 are as follows : 



" miniata 



" General form stellate with broad 

 rays and cnrved interbrachial arcs ; 

 R = 1.7 to 2 r. 



" Papular areas large, with about 

 fifteen to twenty pores on proximal 

 radial regions. 



" Primary abactiual plates rather 

 well spaced with fifteen to twenty-five 

 secondary plates on the intervening 

 meshes of proximal radial region. 



" Medioradial (carinal) series of 

 abactinal plates and armatui'e usual- 

 ly fairly regular and conspicuous prox- 

 imall}-, the crescents being much 

 larger than adradial series. 



" Primary groups of abactinal 

 gi'anules of a wide crescent form, 

 except toward margins, and with 

 many granules (about forty on prox- 

 imal carinals). 



'• Spinelets of actinal combs longer 

 than base line of a comb of four 

 spinelets (much longer than one of 

 three) ; usually three or fom* spinelets 

 to a comb. 



" Serrate seal's on actinal plates 

 larger (difference apparent on com- 

 parison) . 



" pectinifera 



" General form stellato-pentagonal 

 to pentagonal, with nearly straight 

 sides (Mororan, Hokkaido); 11 = 1.4 

 r to 1.5 r. 



" Papular areas small ; less than 

 fifteen papulie on proximal radial 



regions. 



" Primary abactiual plates more 

 closely placed with fewer (five to 

 fifteen) and relativel}' larger second- 

 ary plates on the papular areas of 

 proximal radial region, 



" Carinal series of abactinal plates 

 and their gi-anules not conspicuous- 

 ly larger than adradials, and not form- 

 ing a noticeable series (viewed in- 

 ternally they do, however). 



" The primary groups of abactinal 

 gTanules only exceptional!}' of the 

 wide crescent form (then disk is 

 X^entagonal) but generali}' more el- 

 liptical, or bowed elliptical, with 

 fewer granules (about twelve to twen- 

 ty 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 comparison of specimens.! 

 Usually five or fom-,^^ rarely tlu-ee 

 spinelets to a comb. 



" Serrate scars with fine teeth or 

 bas-relief serrations. 



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



