PART 5 A MONOGRAPH OF THE EXISTING CRINOIDS 145 



History. — Presumably in his preliminary report on the Blake comatiilids published 

 in 1S81 Dr. P. H. Carpenter included under the name of Antedon hagenii specimens of 

 this species which he said had been obtained by the Blake at various stations between 

 Dominica and Grenada at between 75 and 291 fathoms. He said that several indi- 

 viduals from Barbados and Grenada differed so much from specimens from off Sand 

 Key and from one another that he was at first inclined to regard them as representing 

 two new species; but a more careful examination did not confirm this impression. 



Mr. Alexander Agassiz in 1888, quoting Carpenter, said that "Antedon Hagenii" 

 occurred from Dominica to Grenada in 75-291 fathoms. 



In his report on the comatulids of the Challenger Expedition published in 1888, 

 Dr. Carpenter gave Antedon hageni as occurring among the Caribbean Islands and in 

 the Straits of Florida in 82-242 fathoms, again presumably including some individuals 

 of this species. 



In 1921 I recorded as Coccometra hagenii four "small and young specimens" from 

 the University of Iowa's Barbados-Antigua Expedition station 15, remarking that 

 "the segments of Pi are much longer than usual, probably owing to their small size." 

 Reexamination of these specimens showed that they had nothing to do with Coccometra 

 hagenii, and in 1936 I described them under the name of Compsometra nuttingi. 



In 1940 I recorded as Compsometra nuttingi a specimen from Atlantis station 

 3412 and gave notes on it, and in 1941 Dr. H. L. Clark recorded the same specimen. 



[Note by A.M.C] Following Gisleu (1955) this species {nuttingi) is now referred 

 to Antedon together with the others formerly included in Compsometra, but its relatively 

 elongate cirrus segments and the fact that P2 is a genital pinnule mark it off sharply 

 from the other Atlantic species of Antedon. 



ANTEDON LONGICIRRA (A. H. Clark) 



Figure 9,o 

 Compsomclra longicirra A.H. Clark, Notes Leyden Mus., vol. 34, 1912, p. 134 (description; Siboga 



Sta. 167); Unstalked crinoids of the Siboga-Exped., 1918, p. viii (discovery by the Siboga), p. 



204 (in key; range), p. 206 (synonymy; detailed description; Siboga Stas. 50, 167), pp. 271, 273 



(listed), pi. 25, figs. 74, 75, 79. 

 Compsometra gracilipes A. H. Clark, Notes Leyden jMus., vol. 34, 1912, p. 134 (compared with C. 



longicirra), p. 135 (description; Siboga Sta. 50, reef); Unstalked crinoids of the iSt6oja-Exped., 



1918, p. 206 (=C. longicirra), pi. 25, fig. 79. 



Nomenclature [by A.M.C.]. — The transfer of Compsometra longicirra to the genus 

 Antedon renders it liable to confusion with Antedon longicirra Carpenter, 1888, of 

 which it appears, at first sight, to be a junior homonjmi. However, Carpenter's species 

 was transferred to Ptilometra by Mr. A. H. Clark in 1907 and thence to Astcrometra in 

 1909. Under the International Code of Zoological Nomenclature, article 59b, it 

 would only be necessary for me to find a replacement name for Antedon longicirra 

 (A. H. Clark) if I consider the two species to be congeneric. Since this is not the case 

 and is never likely to be, Asterometra longicirra (Carpenter) being a member of the 

 Oligophreata, there is no need to alter the specific name of this species. 



Diagnostic features.- — A small species with the arms not over 40 mm. long, easily 

 distinguished from all the others by the X-XX, very long cirri (more than a fourth 

 the arm length) wliich are exceedingly slender and delicate, almost hairlike, very slightly 

 recurved distally, with aU the 12 to 17 segments much elongated, the earlier with 

 greatly swollen articidations, the outer gradually decreasing in diameter so that the 



