JATANESE ASTEROIDEA. 71 



is mucli more closely aUied to the Noi-tli- Atlantic Ctenodiscm corniculaüis than 

 to the comparatively neighbouring form Ctenodiscus anstralis, from which it 

 is readily distinguished. On the other hand the individual j)oints of difference 

 between the Chilian and the Northern forms are small and trifling, but 

 when taken as a whole mn,j be regarded as sufficient to differentiate them 

 specifically, especially when the constancy of the characters in question and 

 the widely separated geographical j^osition of the two forms are taken into 

 accovuit. 



" Colour in alcohol, a bleached yellowish white. 



" Localities. — Station 308. Off th(^ western coast of South America, off 

 the Chonos Ai'chipelago. December 30, 1875. Lat. 45^ 31' 0" S., long. 

 78° 9' 0" W. Depth 1325 fathoms. Blue mud. Bottom temperature 36°.0 

 Fahr. ; sm'face temperatm*e 54°.8 Fahr. 



" Station 306. In the Messier Channel, between Wellington Island and 

 the west coast of Chili, off Port Gra^^pler. January 4, 1876. Lat. 49"^ 24' 

 80" S., long. 74^ 23' 30" W. Depth 140 fathoms. Blue mud. Surface 

 t<;mperature 53°.0 Fahr. 



" Station 309. Off Puerto Bueno. January 8, 1876. Lat. 50° 56' 0" S., 

 long. 74° 15' 0" W. Depth 40 fathoms. Blue mud. Bottom temperature 

 47°.0 Fain-. ; sm-face temperature 50°. 5 Fahr. 



" Station 311. Off the entrance to Smyth Channel. January 11, 1876. 

 Lat. 52° 45' 30" S., long. 73° 46' 0" W. Depth 245 fathoms. Blue mud. 

 B(->ttom temperature 46°.0 Fahr. ; sm-face temperatm-e 50°.0 Fahr." 



Fewkes ['91, p. 64] gives a brief diagnosis of Ctenodiscus and mentions 

 this species. Bell describes it as follows, with 3 figiu-es ['92, p. 64] : 



"Pt = 2r. 



" General form stellate, with rather deeply incmwed sides, flattened ; a 

 large terminal plate. Ambulacra wide, with large suckers, and bordered by 

 a row of si)ines, three to each plate, and externally to them one or two 

 others, which are generally rather smaller. The ventral sm-face spineless. 

 The marginals with spines ; the superomarginals are elongated from above 

 downwards and form a vertical wall on every side of the disk ; neither on 

 them nor on the inferomarginals is a spine always developed, but it is 



