34 s. GOTO : 



conspicuously eouvox and is grooved with deeply cut and liiglily convoluted 

 striation fniiows. 



" Tlie iMiiniliB are toltjrably numerous, but are large and distinct and 

 limited U) a small area at the base of the ray, which does not extend out- 

 wardly l)e3'ond the first su])ero-marginal after the odd interradial plate, and 

 its inward extent on the disk Avould be bounded by a circle drawn upon the 

 disk, Avith its margin touching the inner edge of the madreporiform body. 



" Colour in alcohol, a l)leaclied ashy white. 



" Individual variation. — In some examples a second infero-raarginal 

 spine, standing below the true lateral spine, is much more strongly deve- 

 lojjed than in others, and this in specimens of the same size and from the 

 sîime localit}". In others again it is represented only by a small miliary 

 spinelet, or ma}' ])e entirely absent altogether. I have only found them 

 well-developed in one case, and that not the largest spacimen in the series. 

 In one example I notica a tendency towards diminution in the number of 

 spinelets in the fuiTow series on the adambulacral j)lates, and this is shown 

 in the abortion or total absence of the outer spinelets at either extremity of 

 the series ; as a result of this reduction there may be only tln*ee, fom-, or 

 five spinelets in pbxce of six, wliich appears to be the normal niunber, 

 and the central spinelets of the series appears comparatively long. The 

 occasional presence of an additional spine on the actiual surface of the 

 adambuLicral plates has already been remarked upon. 



" Young pJictse. — Tlie smallest example in the collection (from Station 

 46) has a minor radial measm-ement of 3.5 mm., and the rays appear to be 

 comparatively robust. This specimen presents in a most unequivocal manner 

 all the characters of the type, and even though so young there need not be 

 the slightest hesitation ab<jut referring the form to this species. So small 

 indeed are the differences between the juvenile and the adult stages, that 

 the matiu'e form in this sj^ecies may well be said to exhibit on a large 

 scale all the featm-es of the embrj'onic phase. 



" In this juvenile example there are no actinal intermediate (ventral) 

 l^lates. The disk and the basa of the raj's have a somewliat villous or 

 subpapill(jse appearance, the spinelets on the abactinal plates being decidedly 



