

Vol. 30, pp. 171-174 October 23, 1917 



PROCEEDINGS 



OF THE 



BIOLOGICAL SOCIETY OF WASHINGTON 



TWO NEW ASTRORADIATE ECHINODERMS FROM THE 

 PACIFIC COAST OF COLOMBIA, AND ECUADOR. 



BY AUSTIN H. CLARK.* 



On her voyage from the Atlantic to the north Pacific in 1887- 

 1888 the Albatross dredged off northwestern South America a 

 magnificent new starfish of the genus Luidia, and a very inter- 

 esting new species of the ophiuran genus Ophiosteira, which are 

 described below. 



Luidia superba, new species. 



Six arms; R=205mm. ; r=30mm.; R:r=6.8:l; width of arms at base, 

 30 mm. ; superomarginal paxillse, 100. 



Arms relatively stout, very gradually tapering to a blunt extremity ; 

 interbrachial arcs very acute ; general form depressed ; no pedicellarise. 



The paxillse, though massive, are in rather open order, especially along 

 the sides of the rays. 



The superomarginal paxillse correspond to the inferomarginals and are 

 closely crowded against them; in shape they are approximately square; 

 they bear centrally seven or eight prominent high rounded tubercles, 

 surrounded by about twice as many similar but more slender tubercles, 

 beyond which are very numerous slender spinelets. 



Within this superomarginal row is another regular row of similar, but 

 smaller, paxillse, five of which correspond to four superomarginals; these 

 are mostly transversely oblong, becoming squarish toward the end of the 

 ray; each of these paxillse is entirely independent of those on either side, 

 and the series is separated from the superomarginal series by a conspic- 

 uous channel. 



Within these again is a third regular series of similar spaced paxilla?, 

 corresponding exactly to those in the second row, from which they are 

 separated by a somewhat broader channel than that separating the second 

 row from the superomarginals; every third or fourth of these paxillse (on 



* Published with the permission of the Secretary of the Smithsonian Institution. 

 42— Proc. Biol. Soc. Wash., Vol. 30, 1917. (171) 



