2 THE VOYAGE OF H.M.S. CHALLENGER. 



called Antedon by de Fremiuville, and Alecto by Leach ; but Lamarck's authority as a 

 zoologist, together with his description of six new species, was sufficient to make his 

 genus more widely known than either de Freminville's Antedon or Leach's Alecto. The 

 very appropriate name Comatula was afterwards used by Miller, Goldfuss, de Blainville, 

 Agassiz, and Midler ; while d'Orbigny 1 gave it an increased importance by founding the 

 family Comatulidae. He referred to this family, however, not merely the various forms of 

 Feather-star, both recent and fossil, in which the base of the calyx is closed below by the 

 cirrus-bearing centro-dorsal piece, but also the remarkable genus Marsupites, which, in 

 the adult condition at any rate, was totally devoid both of stem and of cirri. Further 

 research has shown, however, that Marsupites represents a form of Crinoid which is 

 altogether different from that of the Feather-stars ; and it is now generally considered as 

 the type of another family altogether, the Marsupitidaa. 



The limits of d'Orbigny's family Comatulidaa have varied considerably at different 

 times. Eugeniacrinus and its allies were referred to it by Dujardin and Hupe, 2 whose 

 classification has not been adopted by their successors ; whilst a variety of generic 

 names have been proposed for the numerous fragments of fossil Coniatulse which occur 

 in considerable abundance at certain horizons in the Jurassic and Cretaceous formations, 

 viz., Glenotremites, Solanocrinus, Decacnemos, Decameros, Comaster, Hertlia, and 

 Geocoma. All of these, with one or two possible exceptions, find their place within 

 de Freminville's genus Antedon, as has been explained elsewhere. 3 Some twenty-five 

 years ago this name was revived by Mr. Norman 4 in a more restricted sense than that in 

 which it was proposed by de Freminville ; and this step has been generally followed, with 

 the great advantage of simplifying tbe nomenclature considerably. 



In Midler's earlier writings upon the subject of the Feather-stars, the names Alecto 

 and Comatula seem to have been employed indifferently and as equivalent to one 

 another ; but he was subsequently led to distinguish two different types of Feather-star, 

 one with five ambulacral grooves converging upon a generally central mouth, as in 

 Pentacrinus, and the other with an excentric mouth and fewer than five disk-ambulacra. 

 He therefore considered these as subgenera of Lamarck's original genus Comatula, and 

 while distinguishing the first one by Leach's name Alecto, proposed to call the second 

 type by the new designation Actinometra. 5 Neither of these two subgenera were ever 

 formally defined, and Midler only described three species of Actinometra. A fourth was 



1 Cours elementaire de Paleontologie et de Geologie stratigraphique, Paris, 1852, vol. ii. fasc. 1, p. 138. 



2 Histoire Naturelle des Zoophytes, l^chmodermes, Paris, 1862, p. 186. 



3 See P. H. Carpenter, On the Genus Actinometra, Muller, with a Morphological Account of a new species (Actino- 

 metra polymorpha) from the Philippine Islands, Trans. Linn. Soc. Lond. (Zool.), 1879, ser. 2, vol. ii. pp. 13, 14 ; and also 

 On the Genus Solanocrinus, Goldfuss, and its relations to recent Comatula', Journ. Linn. Soc. Lond. (Zool.), 1880, vol. 

 xv. pp. 196-201. 



4 On the Genera and Species of the British Echinodermata, pt. i , Ann. and Mag. Nat. Hist, 1865, ser. 3, vol. xv. 

 p. 98. 



5 Ueber die Gattung Comatula, Lam., und ihre Arten, Abhandl. d. h. Akad. d. JViss. Berlin, 1849, p. 246. 



