Boone, Echinodermata, Cruises of "Eagle" and "Ara," 1921-28 75 



Or easier armatus Lutken, op. cit., p. 148, 1864. — E. von Martens, 



Monatsb. Akad. Berlin, 1865 ; an English translation of this is in 



Ann. Mag. Nat. Hist., XV, p. 433, 1865. 

 Nidorellia armata A. E. Verrill, Trans. Conn. Acad. Arts and Sci., 



vol. I, p. 280, 1867.— H. L. Clark, Bull. Mus. Comp. Zool., vol. 



52, p. 332, pi. 4, fig. 2, 1910.— Boone, L., Bull. Bingham Oceanog. 



Coll., vol. II, art. 6, p. 3, pi. 1, 1928. 



Genus : ASTROPECTEN Linck. 

 Astropecten antillensis Lutken. 



Plates 31 and 32. 



Type: Lutken 's type came from St. Thomas, W. I., and is deposited 

 in the Copenhagen Museum. 



Distribution : This is one of the less abundant of the West Indian 

 species of Astropecten, having been recorded from St. Thomas ; Guade- 

 loupe and Porto Padre, Cuba. 



Material examined: Two specimens, collected at Porto Padre, 

 Cuba, March, 1928. 



Habits: This species is reef -dwelling and spends a great deal of 

 its time buried in the sand, but is also very agile and can move about 

 rapidly. 



Technical description : Verrill considers this species very closely 

 allied to Astropecten duplicatus and that it may possibly prove to be 

 only a local variety of this species. A. antillensis is also closely allied 

 to A. orasiliensis Muller and Troschel, but Perrier, who has examined 

 the types of both species, considers the species distinct. 



The "Ara" specimens are of about the same size. The slightly 

 larger one is regularly stellate with five, slender, tapered rays. 

 R = 43 mm., r = 10 mm. The superomarginal plates are 28 to each 

 side of each ray, rectangular, except the innermost one and the one 

 at the tip of each ray. Each superomarginal plate has its dorsal 

 surface nearly square, and its lateral surface similar, the width of the 

 plate being slightly less than one-half of its entire length ; there is a 

 stout, conical spine on each plate, arising from the center and forming 

 a marginal series. There is also an incomplete row of similar spines 

 on the plates of the superomarginal series from the interbrachial angle 

 extending half way to the tip of each ray. The inferomarginal plates 

 are opposite the superomarginals, and bear each two long, flattened, 

 bluntly rounded slender marginal spines ; the ventral surface of these 



