110 s. goto: 



aud presents a sharp angular peak, tlie moutli-platss sloping down tliere- 

 from "with a gracefnl inward ciu*ve to tlie level of the intsrbrachial area. A 

 single short conical mouth-spine is placed at the extremity of the adorai 

 peak ; and two others, about equal in size to the ambulacral spines, stand 

 on the lateral margins of each plate, the most adorai of the two being 

 situated nearly midway between the extremities of the margin. 



" The actinal interbrachial areas are small and sagittiform in outhne, 

 and do not extend beyond the third adambulacral plate. The plates are 

 small, subregular, transversely elongate on the outer j)orfcion of the area, and 

 with a tendency to imbricate, this character, however, being so faintly 

 presented that it is difficult to say whether imbrication really exists or not. 



" Colom-, in alcohol, greyish wliite, rather darker over the dorsal area 

 of tlie disk. 



" Station 237. Lat. 34° 37' N., long. 140° 32' E. Depth 1875 fms. ; 

 bottom temperatm^e 1°. C. ; red clay." 



Substantially the same description is reproduced in the full report of 

 the " Challenger," with addition of the locality and some remarks [Sladen, 

 '89, p. 140] : 



" PorceUanaster tuherosus, Sladen (PI. XXm. figs. 1-4; PI. XXVII. 

 figs. 13-16). 



[Reference to the foregoing description omitted.] 



"Kays five. 11 = 18.5 mm. ; r=6mm. R = 3r. 



" The rays spring gradually from the angles of the disk and taper 

 moderately towards the extremity, maintaining a robust character tlu'oughout ; 

 the minor radius is in the proportion of 32 per cent. The disk is not liigh, 

 and very slightly inflated. Tlie interbrachial arcs are well roimded. 



" The abactinal area is covered with a rather fleshy integument beset 

 with simple spinelets somewhat closely x^laced ; these are short, cylindrical, 

 obtuse, C3vered with membrane, and occupy the whole of the sm-face except- 

 ing only the extreme angle at the base of the ray. A well-developed 

 epiproctal tubular prolongation rises from the centre of the abactinal area, 

 and is nearly equal in length to the distance between the centre and the 

 inner edge of the marginal plates in the interbrachial arc ; it tapers very 



