254 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



Professor Gisle"n wrote that when in 1922 he described the new genus Clarkomdra 

 he placed it in the subfamily Perometrinae of the Antedonidae, but that hi 1936 I 

 as it seems to him quite correctly transferred it to the Colobometridae. He remarked 

 that Embryometra is still another very difficult intermediate link between the Colo- 

 bometridae and some types of the Antedonidae. He said that on the basis of the 

 diagnosis Embryometra falls outside the Colobometridae, but a careful investigation 

 of its characters seems to place it as a near relative of that family. 



He recalled that in 1924 he pointed out that the Macrophreata must be considered 

 as a group of polyphyletic origin, and that there are probably series within the Ante- 

 donidae which have their ancestors near the Colobometridae. The evolution within 

 the comatulids proceeds toward an ideal type, more or less antedonid in appearance, 

 and therefore a decision regarding the systematic position may in some cases be 

 rendered extremely difficult. The new form Embryometra seemed to him one more 

 proof for his opinion. 



The young of nearly all comatulids, and the very small species, converge toward 

 a generalized type in which the characteristic features of the group to which they 

 may belong tend to become more or less obscured, and the fully grown individuals 

 in most of the subfamilies of the Antedonidae diverge from this generalized type less 

 than the other comatulids. But in my opinion this does not indicate that the charac- 

 teristic features of the various groups are not fundamental. The short, stout, strongly 

 recurved cirri of Embryometra closely resemble those of many small species in the 

 Colobometridae and are not found in any species in any subfamily of the Antedonidae. 

 The antedonid features found hi Embryometra I believe to be purely a result of that 

 generalization usually associated with small size, without further significance. 



Localities.- Dr. Th. Mortensen's station 56; southwest of False Bay, Cape of 

 Good Hope (lat. 3417 S., long. 1758' E.); 293 meters; mud; December 17, 1929 

 [Gisl6n, 1938]. 



Dr. Th. Mortensen's station 57; southwest of False Bay, Cape of Good Hope 

 (lat. 3421' S., long. 1757' E.); 325 meters; mud; December 19, 1929 [GislSn, 1938]. 



Geographical range. Only known from southwest of the Cape of Good Hope, 

 South Africa. 



Bathymetrical range. From 293 to 325 meters. 



Remarks. This species is known only from the four specimens dredged by 

 Dr. Th. Mortensen in 1929 and described by Professor Gisl6n in 1938. 



UNIDENTIFIABLE SPECIES 

 IANTEDON IMPINNATA P. H. Carpenter) 



Antedon impinnata VON GRAFF, Challenger Reports, Zoology, vol. 10, pt. 27, 1884, pp. 15, 16, 18, 50, 

 60 (nomen nudum; North Bay, Mauritius, 15 fms. ; myzostomes) . P. H. CARPENTER, Challen- 

 ger Reports, Zoology, vol. 26, part 60, 1888, p. 54 (10-armed species), p. 206 (in key to anomalous 

 10-armed species), p. 366 (found above 20 fms.), p. 378 (Mauritius, 15 fms.). BRAUN, Cen- 

 trabl. Bakteriol. und Parasitenk., vol. 3, 1888, p. 210 (myzostomes). HAMANN, Bronns Klassen 

 und Ordnungen des Tier-Reichs, vol. 2, Abt. 3, 1907, p. 1580 (listed). A. H. CLARK, Proc. 

 U. S. Nat. Mus., vol. 40, 1911, p. 47 (synonymy; diagonsis; unidentifiable; locality); Crinoids of 

 the Indian Ocean, 1912, p. 34, 284 (same). GISLEN, Nova Acta Reg. Soc. Sci. Upsaliensis, ser. 

 4, vol. 5, No. 6, 1922, p. 142 (possible, but not likely, that this is closely related to C. elegans). 

 A. H. CLARK, John Murray Exped. 1933-34, Sci. Reports, vol. 4, No. 4, 1936, p. 102 (inde- 

 terminable). 



