354 CLARK. 



well-known West Indian species common at Bermuda. The other 

 species taken by the Station party were four sea-stars, three brittle- 

 stars and two sea-urchins, and of these nine, one represents a species 

 hitherto undescribed, and three others are not known from Bermuda. 

 As the sea-star Chaetaster is also unknown from Bermuda itself, it 

 appears as though nearly half the echinoderms found on the Chal- 

 lenger Bank have not made their way across the three or four miles 

 of deep water that separate them from Bermuda. 



All the Echinoderms at present known from the Challenger Bank 

 are referred to below but there is every reason to believe that the list 

 would be greatly augmented by more thorough exploration. 



ASTEROIDEA: SEA-STARS. 



Chaetaster nodosus. 



Perrier, 1875. Arch. Zool. Exp., 5, p. 146 (330 of reprint). 

 Verrill, 1915. Bull. Univ. Iowa, n. s. no. 92, p. 116; pi. VIII. 



The unique holotype of this species was recorded as from " Guade- 

 loupe. M. Duchassaing, 1870," but no specimens were taken by 

 either the Blake in her extensive dredgings in the West Indies, 1877- 

 79, or by the Albatross in 1884-87. The expedition from the Uni- 

 versity of Iowa took two specimens in rather deep water (140-200 

 fms.) off Havana, Cuba, which in size and appearance were very simi- 

 lar to the holotype. One of these was described and well figured by 

 Verrill, /. c. The Challenger took specimens of Chaetaster at her 

 Station 36, off Bermuda, 30 fms., but Sladen (1889, Challenger 

 Asteroidea, p. 399) regarded them as examples of the Mediterranean 

 species, longipes, although he says "a number of the examples" from 

 Bermuda have here and there tubercular enlargements of the paxillae" 

 like those characteristic of nodosus. Unfortunately he gives no infor- 

 mation as to the number, size or form of these specimens from the 

 Challenger Bank, data which would now be of veiy great value. 

 Verrill (1. c.) suggests that these specimens taken by the Challenger 

 are probably nodosus and not longipes. Examination of the six speci- 

 mens in the Museum of Comparative Zoology collection, all from the 

 Challenger Bank, shows positively that they are not longipes and 

 Sladen was no doubt in error in referring his Bermudan material to 

 that species. For longipes has well-marked series of actinal inter- 

 mediate plates extending far out on the arm, and even in a specimen 

 with R only 24 mm., one of these series is evident. These inter- 



