226 DISCOVERY REPORTS 



There is much variation in the frequency of diplacanthid adambulacral plates. In the 

 largest specimen (R 66 mm.) only the plates of the proximal third of ray are diplacan- 

 thid, the rest having i spine, with a few scattered plates bearing 2. 



There is no trace of papulae between the inferomarginal and actinal spines, nor any 

 between the latter and adambulacral plates. 



In the largest specimen, on the actinal surface on either side of interradial line, and 

 between inferomarginal and actinal plates, is what I interpret as a gonopore. There are 

 thus two in each actinal interradial area. The gonads are attached to body wall at lower 

 end of first superomarginal plate, thus well above the pore. 



Distribution. Ross Sea and South Victoria Land, 30-351 m. ; Antarctic Archipelago 

 (Alexander I Island), 297 m. ; latitude 64° 32' to 66° 55' S and longitude 92' to 145° 51' 

 E, 60-354 fathoms; hence probably circumpolar. 



Notasterias stolophora sp.nov. 

 (Fig. J, i-if, zb; Plate XVII, fig. 4) 



Diagnosis. Differing from A^. armata in having smaller macrocephalous pedicellariae 

 distributed in true circumspinal wreaths on the carinal plates and half wreaths on the 

 marginal, and in having actinal papulae. R 27 mm., r 6-5 mm., br 7 mm. Colour in life 

 pale yellow-green. 



Description. Spines subequal, prominent, spaced, with compressed, truncate or 

 subclavate tips, in 5 longiseries. The carinal spines are on every plate on the proximal 

 third of ray, then on alternate plates. The superomarginals are generally in ahernate 

 plates, while each inferomarginal plate carries i spine. The carinal plates carry promi- 

 nent wreaths of pedicellariae while the marginals have half-wreaths on the upper or 

 adcarinal side. The skeleton is similar to that of A^. armata. There are two dorsolateral 

 series of single papulae (i series close to carinals and i close to superomarginals), i 

 intermarginal series, and a short actinal series, comprising 3-5 single papulae. The inter- 

 marginal papulae, mostly single, are large and the intermarginal area is as broad as the 



dorsolateral. 



Integument thick and wrinkled, as are the spine sheaths except at spine tips where 

 skin is strongly contracted. Well-defined transverse channels extend from dorsal 

 surface between marginal plates to ambulacrum and include between them usually 

 three adambulacral plates. 



Adambulacral plates diplacanthid except for first 1-3, which are monacanthid. Spines 

 slender, terete, blunt, subequal to inferomarginals but much less robust. At each mouth 

 angle are 4 spines, the middle pair longer than the lateral spine and shorter than the 

 adambulacrals. Behind these are two prominent suborals slightly larger than adam- 

 bulacrals. The adoral carina is composed of the first 2 pairs of adambulacral plates. 



Crossed pedicellariae are solely of the large macrocephalous variety in diflFerent 

 stages of development. When fully developed they are o75-o-8 mm. long and 0-3- 

 0-4 mm. broad at the basal piece. They are thus very much smaller than in armata, as 



