A MONOGRAPH OF THE EXISTING CRINOIDS 351 



are peculiar in having a very large articular facet in the center from which radiating 

 processes extend all around to the margin of the socket. The dorsal surface of the 

 radial pentagon is marked by a well defined basal star the angles of which do not, 

 however, appear externally. The central funnel of the calyx is smaller than in Stire- 

 metra breviradia, as the ventral ends of the muscle plates are less everted than in that 

 type. Carpenter said there is a further resemblance between this species and the 

 mature Stiremetra breviradia in the presence of transverse ridges and furrows at the 

 lower ends of the muscular fossae; but he said he had found two radials without them 

 in a calyx of basicurva. 



At the British Museum I examined five specimens of this species from Challenger 

 station 170A and remarked that it had been well figured by Carpenter. After examining 

 these same specimens Gislen noted that the cirri are stout with a longitudinal carination 

 and the opposing spine in the form of a transverse crest. 



Locality.— Challenger station 170A; near the Kermadec Islands, north of New 

 Zealand (lat. 29°45' S., long. 178°11' W.); 1,152 meters; bottom temperature 4.17° C; 

 volcanic mud; July 14, 1874 [von Graff, 1884, 1885; P. H. Carpenter, 1884, 1888, 1891; 

 Braun 1888; Hartlaub, 1895; Bather, 1900; Hutton, 1904; Minckert, 1905; Hamann, 

 1907; A. H. Clark, 1907, 1908, 1909, 1912, 1913, 1918; Gislen, 1928] (5, B. M.). 



Doubtful locality— Challenger station 175; near Kandavu, Fiji (lat. 19°02' S., 

 lono- 177°10' E.); 2,468 meters; bottom temperature 3.33° C; globigenna ooze; 

 August 12, 1874 [P. H. Carpenter, 1888]. Carpenter said that only two comatulids are 

 recorded in the station book as having been found at this locality, and as the depth 

 is considerable he had little doubt that they were the two small species Stiremetra 

 breviradia and S. acutiradia. The arms of the latter were all loose and Carpenter said 

 it is quite possible that the few arm fragments of Charitometra basicurva may have been 

 among them; but no calyx of this species was obtained. 



History.— Antedon basicurva was first mentioned by Prof. Ludwig von Graff in his 

 account of the myzostomes of the Challenger expedition published m 1884. The name 

 was a nomen nudum. He gave the locality as Challenger station 170. In his report on 

 the stalked crinoids of the Challenger expedition published m the same year Dr. 1 H. 

 Carpenter gave a short note on the plating of the disk in Antedon basicurva, for which 

 he gave a specific formula, and figured a portion of a distal pinnule showmg the side and 

 covering plates as well as the disk. In the report on the comatulids of the Challenger 

 expedition published in 1888 Carpenter described Antedon basicurva m detad and figured 

 it. In the same year Braun listed it as the host of certain myzostomes, taking his 

 information from von Graff. . 



In 1891 Carpenter compared Antedon basicurva with Antedon (Stiremetra) lusitamca, 

 and in 1895 Dr. Clemens Hartlaub discussed its systematic and bathymetrical re- 

 lationships Dr. F. A. Bather in 1900 published a figure of a portion of a distal pinnule 

 with the side and covering plates redrawn from the figure published by Carpenter in 

 1884. Captain Hutton listed Antedon basicurva as a New Zealand species in 1904, 

 Minckert discussed the syzygies in 1905, and Hamann listed it in 1907. 



In my first revision of the old genus Antedon published in 1907 basicurva was 

 transferred to the new genus Charitometra. Charitometra basicurva was mentioned as the 

 type of an oceanic group in 190S, and was listed in 1909. In my memoir on the crinouls 

 of the Indian Ocean published in 1912 Charitometra basicurva was listed and the 



