A MONOGRAPH OF THE EXISTING CRINOIDS 239 



University of Iowa's Barbados-Antigua expedition station 51 ; Barbados [A. H. 

 Clark, 1921] (1, U. I. M.). 



University of Iowa's Barbados-Antigua expedition station 70; Barbados [A. H. 

 Clark, 1921] (arm fragments, U. I. M.). 



University of Iowa's Barbados- Antigua expedition station 79; Barbados [A. H. 

 Clark, 1921] (arms, U. I. M.). 



University of Iowa's Barbados- Antigua expedition station 85; Barbados [A. H. 

 Clark, 1921] (part of an arm, U. I. M.). 



University of Iowa's Barbados-Antigua expedition station 92; Barbados [A. H. 

 Clark, 1921] (arms, U. I. M.). 



University of Iowa's Barbados-Antigua expedition; Barbados [A. H. Clark, 

 1921] (1, and fragments of another, U. I. M.). 



Blake station 231; off St. Vincent (lat. 13 12' 10" N., long. 61 17' 18" W.); 

 174 meters; temperature 16.39 C.; sand and broken shells; February 20, 1879 

 [Hartlaub, 1912] (1, M. C. Z., 430). 



Albatross station 2142; Gulf of Darien, southwest of Cartagena, Colombia (lat. 

 9 30' 15" N., long. 76 20' 30" W.); 77 meters; green mud and sand; March 25, 

 1884 (1 + , U.S.N.M., 34530, 34531). 



Albatross station 2146; northeast of Colon, Panama (lat. 9 32' 00" N., long. 

 79 54' 30" W.); 62 meters; broken shells; April 2, 1884 [A. H. Clark, 1917] (5 + , 

 U.S.N.M., 25458, 34498, 34499, 36251, 36277). PI. 20, fig. 48. 



Geographical range. From northern Cuba to Barbados, St. Vincent, and the 

 Gulf of Darien. 



Bathymetrical range. Sublittoral, and down to 355 meters; the average of 12 

 records is 203 meters, but undoubtedly the usual habitat is in shallower water. 



Thermal range. From 16.11 C. to 20.56 C.; the average of 4 records is 17.95 

 C.; but all these records are from deep water. 



History. The first reference to this species was published by Prof. Ludwig von 

 Graff, who in one of his contributions on the myzostomes (1884) mentioned Actino- 

 metra discoidea from Blake stations 155 and 203 as a host. This name was furnished 

 him by Dr. P. H. Carpenter, and occurs simply as a nomen nudum. 



In the Challenger report (1888) Carpenter gave a specific formula for this species 

 which was identical with that which he gave for lineata (rubiginosa). He inserted 

 discoidea in his key to the species of the Fimbriata group of Actinometra, indicating 

 that it differs from lineata (rubiginosa) in having the brachials "almost quadrate" 

 instead of "triangular, nearly as long as wide." The range he gave as "Caribbean 

 islands" in 88-118 fathoms. 



In 1912 Hartlaub described this form in detail, with figures, under the name 

 of Actinometra echinoptera var. discoidea. In his list of the varieties of Actinometra 

 echinoptera and the localities where they were found he also mentioned it from 

 Blake station 231 under the name of Actinometra echinoptera var. rubiginosa-discoidea, 

 but no mention of this is made in the text. In addition to specimens from Blake 

 stations 155, 177, 203, and 231, Hartlaub described in detail 2 examples from 

 Barbados in the Kiel Museum which had been collected by Captain Werner in 1873. 



