EEPOKT ON THE ASTEEOIDEA. 281 



these knobs to form a small lineal series slightly oblique in relation to the aboral margin 

 of the plate. 



The adambulacral plates are considerably broader than long. Their armature consists 

 of a furrow series of three short, robust, slightly tapering but obtusely tipped spinelets, 

 radiating slightly apart ; and the median spinelet is rather larger than its companions. 

 On the actinal surface of the plate are two thick, short, robust, obtuse, stumpy spinelets ; 

 and on the inner half of the ray frequently three, placed one behind the other. These arc 

 so large that they leave no room on the plate for anything but an occasional and irregularly 

 placed granule. The margin of the plate is surrounded by a single series of large bead- 

 like granules distinctly spaced. 



The actinal interradial areas extend as far as the fourth infero-marginal plate, and are 

 covered with large plates or tabula, which resemble those on the abactinal area. The 

 tabula are margined by bead-like granules, the separate plates being thus distinctly 

 marked, and each plate bears from one to three short, robust, obtuse, papilliform granules or 

 spinelets similar to those on the actinal surface of the adambulacral plates, all increasing 

 slightly in size as they approach the mouth. 



The mouth-plates are large but not prominent. Their armature consists of a marginal 

 series of four spines on each plate, which increase in size as they advance inward. There 

 is thus a pair of large, cylindrical, obtusely tipped spines at each mouth-angle directed 

 over and closing the actinostome. On the actinal surface of the plates are two large, 

 robust, cylindrical spinelets, slightly larger than any of the other large obtuse spinelets 

 on the actinal surface, and behind these are two granules forming with the two secondary 

 or superficial spines just mentioned a lineal series. 



The tube-feet have large sucker disks ; and the ambulacral furrows are narrow and 

 closed over by the armature of the adambulacral plates. 



The anal aperture is subcentral and margined by one or two rings of granules, the 

 inner series small, the outer larger and more irregular. 



The madreporiform body is conspicuous and situated about midway between the 

 centre and the margin. Its surface is slightly convex and is marked with fine striation- 

 furrows, which are much convoluted and meandriform. 



Colour in alcohol, a bleached ashy or yellowish white. 



Locality. — Simon's Bay, Cape of Good Hope. Depth 5 to 18 fathoms. 



Remarks.— This species is readily distinguished from Calliaster childreni, Gray, the only 

 other species of Calliaster at present known, by the obtuse and non-tapering rays, as well 

 as by the less tumid supero-marginal plates, which distinctly increase in breadth as they 

 approach the extremity, whilst in Calliaster childreni they slightly diminish. Calliaster 

 baccatus is further characterised by the more numerous spines on the abactinal plates, 

 which are more stumpy, as well as by the much coarser and peculiar bead-like granules 

 that surround the tabula. In Calliaster childreni only the medio-radial series of tabula 



(ZOOL. CHALL. EXP. — PART LI.— 1888.) 36 



