CRINOIDEA AND ECHINOIDEA 



27 



Csenopedina cubensis 



A. Agassiz, 1869. Bull. M. C. Z., 1, p. 256. 1872, Rev Ech,, pi. Ill, figs. 



1-7 (as Hemipedina cuhensis). 



The Bahama Expedition was so fortunate as to secure two 

 specimens of this very rare sea-urchin. One of these (St. 58) 

 is an unusually fine specimen, 22 mm. in diameter; the pri- 

 mary spines are 27 mm. long but all are broken at the tip ; they 

 are of a yellow-green color while all the smaller ones are white. 

 This is the largest specimen I have seen but Koehler (1909, 

 Princesse-Alice Ech., pi. 1, fig. 1) gives a fine colored figure 

 of a specimen about 35 mm. in diameter, with primary spines 

 66 mm. long. The second specimen secured by the Bahama Ex- 

 pedition is only 13 mm. in diameter and has lost all of its 

 spines. 



This species is not referred to in the ''Narrative" of the ex- 

 pedition, and there are few references to it elsewhere in 

 literature. It is not included in the Blake report among the 

 echini taken by the Blake but there is a small specimen in 

 the M. C. Z. taken at piake St. 320, off Georgia, in 257 fms. 

 According to Yerrill (1885, Albatross ExpL, p. 49) the 

 Fish-Hawk took a specimen in 1882 off the eastern coast of 

 the United States in 194 fms. The only station occupied by the 

 Fish-Hawk in 1882, with a depth of 194 fms. was near Nan- 

 tucket. The Princess-Alice took one specimen in 1901 near 

 the Canary Islands in 610 fms. and two specimens in 1902 near 

 the Azores Islands in 659 fms. Evidently the species is wide- 

 spread in the North Atlantic but in much deeper water on the 

 eastern side than near the American coast. 



In my key to the species of Csenopedina (1912, Mem. M. C. 

 Z., 34, p. 217) there is a very unfortunate lapsus calami which 

 vitiates one of the distinctions between C. ciihensis and C. in- 

 dipa. The comparison made between ' ' actinostome " and ''peri- 

 proct" should be between actinostome and the entire ahactinal 

 system. In cuhensis, the actinostome is distinctly smaller than 

 the abaetinal system, while in i^idica they are of about equal 

 size. 



The Bahama Expedition took cuhensis at the foUomng 

 places : 



