A MONOGRAPH OF THE EXISTING CRINOIDS 283 



University of Iowa's Barbados-Antigua expedition station 56; Barbados [A. H. 

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



University of Iowa's Barbados- Antigua expedition station 59; Barbados [A. H. 

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



University of Iowa's Barbados-Antigua expedition station 67; Barbados [A. H. 

 Clark, 1921] (5, U. I. M.). 



University of Iowa's Barbados-Antigua expedition station 78; Barbados [A. H. 

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



Blake; Grenada or Martinique (3, M. C. Z., 427). 



Blake station 246; off Grenada (lat. 12 05' 45" N., long. 61 45' 40" W.); 

 281 meters; temperature 13.33 C.; dark gray ooze; February 25, 1879 [Hartlaub, 

 1912] (2, M. C. Z., 421). 



Blake station 249; off Grenada (lat. 11 48' 15" N., long. 61 48' 45" W.); 

 479 meters; temperature 8.33 C.; coarse sand; February 27, 1879 [von Graff, 1883, 

 1884; Hartlaub, 1912] (21, M. C. Z., 217, 220, 223, 422). 



Blake; label lost (13, M. C. Z., 426). 



No label; presumably Blake (1, M. C. Z., 444). 



Albatross station 2142; eastern part of the Gulf of Darien, Colombia (lat. 9 

 30' 15" N., long. 76 20' 30" W.); 77 meters; March 23, 1884 (1, U.S.N.M., 34823). 



Geographical range. Throughout the Caribbean Sea and Gulf of Mexico. 



Bathy metrical range. From 24 to 479 (?510) meters; the average of 30 records 

 is 214 meters. This species is, however, common in shallower water than is indicated 

 by the records. 



Thermal range. From 8.33 C. to 24.72 C.; the average of 15 records is 18.05 

 C. This species is common in water which is warmer than the records would 

 indicate. 



History. This species was first mentioned in 1883 by Prof. Ludwig von Graff 

 in his account of the myzostomes in the Blake collection. He referred to it as Acti- 

 nometra meridionalis var. carinata, the name having been furnished him by Dr. P. H. 

 Carpenter, and recorded it from Blake station 249. In the following year in his 

 account of the myzostomes collected by the Challenger he again mentioned it and 

 recorded it from Blake stations 249 and 203. 



Finding in the collection of the United States National Museum a number of 

 specimens of a small 10-armed species evidently allied to the species of Nemaster 

 and Neocomatella, it never occurred to me that they could represent what Carpenter 

 had designated as variety carinata of Comactinia meridionalis, a wholly different 

 type belonging to a widely different group, and I accordingly in 1909 described them 

 under the name of Leptonemaster venustus. 



On the appearance of Hartlaub's monograph on the Blake comatulids in 1912 

 I at once recognized in his Actinometra echinoptera var. carinata my Leptonemaster 

 venustus. Other specimens of the same species were also described under the names 

 Actinometra echinoptera var. carinata-pulchella, Actinometra echinoptera var. carinata- 

 discoidea, Actinometra echinoptera var. meridionalis, and Actinometra echinoptera var. 

 meridionnMs-ca-rinafn. 



