432 



MR. W. P. SLADEN ON THE ASTEROIDEA 



area between the marginal plates, the last two or three of which 

 meet in part of their length, and thus disconnect the median 

 series. 



Ceibbelladensispina, sp. nov. PI. VIII. figs. 5, 6, 7, 8, 9. 

 Coll. St. John : Korean Straits, W. coast of Niphon, 40 

 fathoms. 



Arms rounded and very uniform in thickness throughout their 

 length, tapering only slightly and very gradually towards the ex- 

 tremity, which is blunt and well rounded. Arms slightly flattened 

 at the base, and quite continuous with the disk, being separated 

 by no interradial depression ; arm-angles well rounded. The 

 ossicles of the rays and disk are covered very densely with small 

 closely-crowded spinelets, so closely packed as to suggest to the 

 naked eye the granulate appearance of Linckia. The spinelets 

 are built-up of multiradiate laminae, and by expansion at the tip 

 assume a clavate form. The intermedial pore-arms are very small, 

 quite disconnected and enclosed ; they are frequently furnished 

 with one papilla only ; but two or occasionally even three occur. 



The madreporiform body is nearer to the centre than the mar- 

 gin of the disk ; and the septa, which radiate in straight lines from 

 its centre, are closely studded with spinelets similar to those of 

 the disk and rays. 



The foot-papillae are more robust than the spinelets of the dorsal 

 or lateral portions of the ray, and are placed in oblique pairs upon 

 the adambulacral plates. The inmost pair, or that nearest the 

 furrow, are longer and much stouter than the others, and are suc- 

 ceeded by four or five similarly oblique pairs of smaller spinelets, 

 foUowing'^in series and gradually diminishing in size and thick- 

 ness until they merge imperceptibly into the densely packed spi- 

 nulation of the ventro-lateral j^lates. 



The specimen measures E=:25 millims., r=5 millims. ; breadth 

 of a ray midway between the tip and disk, 4 millims. 



ASTERACANTHION RUBENS {Linne), var. MIQRATUM, miJii. 



Coll. St. John : Korean Straits. 



Two small specimens, their greatest radius measuring 16 

 millims. and 12 millims. respectively. Although only in a young 

 and premature stage of growth, I feel little hesitancy in assigning 

 these starfish to the above widely spread species. 



The ambulacra! papillae are short, moderately stout, and cylin- 

 drical, and arranged two and one alternately upon the interam- 



