2 BULLETIN 82, UNITED STATES NATIONAL MUSEUM VOLUME 1 



sockets so characteristic of the Atelecrinidae does not obtain in Notocrinus, and accord- 

 ingly it can not be referred to that family either. Thus the family Antedonidae alone 

 remains. Mortensen pointed out that the arrangement of the cirrus sockets in columns 

 agrees with the subfamily Zenometrinae ; but otherwise the characters of the centro- 

 dorsal, and the central pore and the large basal groove, do not correspond with this 

 family; besides, the short, stout oral pinnules, the plating of the disk, and the retention 

 of the basals and of the anal plate are characters not normally met with in the Ante- 

 donidae. Finally, Mortensen believed that the unique character of the genital organs 

 seems to preclude the idea that Notocrinus can be referred to the Antedonidae any 

 more than to any of the other families of comatulids. That this is not a special adapta- 

 tion to the viviparous habit is evident, according to Mortensen, from the fact that the 

 males also have the genital organs in the arms, not in the pinnules. Mortensen created 

 for this new type the family Notocrinidae, which he assigned to the Macrophreata. 



In a revision of the classification of the comatulids published in 1924 Dr. Torsten 

 Gislen defined the superfamily Thalassometrida (corresponding essentially to the super- 

 family Tropiometrida as herein understood) and divided it into two subtribes, the 

 Thalassometrida, s. s., and the Notocrinida (see Part 3, pages 62, 63). The Noto- 

 crinida he divided into two sections, one in which the side- and covering-plates are 

 moderate, the brachials and pinnule segments are rounded, and the gonads are in the 

 arms, including only the family Notocrinidae; and another in which the side- and 

 covering-plates are well developed, the brachials and pinnule segments are prismatic 

 triangular in cross section- and the gonads are in the pinnules, including the single 

 new family Asterometridae (Asterometra and Pterometra). Dr. Gislen's conclusions 

 were based on a very detailed study of some of the type specimens of Notocrinus virilis. 



The author in Part 3 of the present work (page 65) placed the family Notocrinidae 

 in the suborder Macrophreata, following Mortensen. Up to that time he had seen 

 no specimens of Notocrinus virilis. 



In his report, published in 1929, on some recent crinoids in the British Museum, 

 he placed the family Notocrinidae in the Macrophreata, following the Antedonidae. 



Since then he studied in great detail the series of eight specimens collected by the 

 Australasian Antarctic Expedition under the direction of Sir Douglas Mawson, and 

 this study convinced him that the family Notocrinidae is really referable to the Oligo- 

 phreata, as determined by Gislen, though it can not be referred to any one of the three 

 superfamilies included in that suborder. 



The most practicable course seems to be to take Gislen's subtribe Notocrinida, 

 redefined so as to exclude the Asterometridae (here referred to the Tropiometrida) 

 and raise it to the rank of a superfamily which would find its most logical place between 

 the superfamilies Mariametrida and Tropiometrida. 



With the family Notocrinidae in the superfamily Notocrinida, is placed the family 

 Aporometridae, including the single genus Aporometra. The reasons for including the 

 Aporometriclae in the same superfamily with the Notocrinidae are given on page 23. 



The first published notice of the superfamily Notocrinida as understood herein 

 was in 1938 by Dr. H. L. Clark who quoted (by permission) from a letter from the 

 author in which he said that "The most satisfactory disposition of the Notocrinida 

 would seem to be to consider it as a suborder [i.e., superfamily] within the Oligophreata, 

 equivalent to, and on the same basis as, the Comasterida, Mariametrida and Tropio- 

 metrida." 



