birdVfoot sea-star. 117 



The BirdVfoot Starfish is a very singular species. 

 It is the thinnest and flattest of all its class. When alive, 

 it is flexible, like a piece of leather ; and a person who had 

 never seen it before, would be apt to mistake it for the 

 torn away dorsal integument of some gibbous Goniaster. 

 It is white, with a red centre, and five red rays proceeding 

 from it to the angles, and the margin is generally bordered 

 with red. The upper surface is covered with spiniferous 

 tubercles, which are arranged differently on the white and 

 coloured parts. On the red disk and radiations they are 

 smaller and closer together than on the rest of the body, 

 and are arranged irregularly. On the white portions they 

 are arranged in regular rows, the largest tubercles being 

 towards the disk. On the red margins they are very small, 

 and closely placed in regular rows, running from the edge 

 towards the centre. Each of these marginal rows has a 

 tuft of spines at its extremity, projecting beyond the out- 

 line of the body. The spines are short, acute, very 

 numerous, and radiate on the summits of the somewhat 

 oblong tubercles. When they are rubbed away in a dried 

 specimen, the surface of the skin appears regularly tes- 

 selated. The madreporiform tubercle is small, flat, striat- 

 ed, and placed towards the centre of the disk. Beneath, 

 the spiniferous tubercles cover the triangular spaces, and 

 are arranged in regular rows. They differ greatly in form 

 from those above, being linear, and bearing the spines in 

 a single row of from five to nine in number, the central 

 ones longest. This arrangement gives a pectinated ap- 

 pearance to the tubercles. The avenues are bordered by 

 longitudinal fasciculi of larger spines ; those immediately 

 around the mouth are largely developed. At each angle 

 the margin is notched, and forms a little hood for the 

 protection of the eye. 



