16 MR. P. H. CARPENTER ON THE GENUS ACTINOMETEA. 



tyi^e possessing ceitaiii definite characters, by which it may be distinguished from other 

 types forming the centres of similar groups of varieties ; but the characters above men- 

 tioned are usually so excessively variable within each group, that it becomes utterly 

 impossible to make any use of them as specific distinctions, as Dujardin has done. 



Dujardin seems to have detected Miiller's oversight in classing the Aste7'ias multi- 

 radiata of Retzius as an Alecto after previously describing it as an Actinometra; for he 

 transferred it to this genus under the name of Aclinomctra miiltiradiatu, and adopted 

 MuUer's specific designation imiltifida for the original specimens described as Comatula 

 multiradiaia by Lamarck. The third form to which this name has been applied, viz. the 

 C muUiradlata of Goldfuss, was regarded by Dujardin as a sepai'ate genus on account 

 of its i^ossessing external basals, or, as he called them, " intcrradials ;" and he restored to 

 it the old name of Comaster, which had been given up by Miiller, including in this genus, 

 as Rocmcr had previously done, all the species of Solanocrinus. 



(§ 12) Miiller had, as we have seen above, referred both Alecto and Act in 077ie(r a to the 

 one genus Comatula, while Dujardin limited the application of the latter name to the 

 species oi Alecto only, and gave up the name of Alecto altogether, as had been previously 

 done by D'Orbigny and Pictet. This was a step in the right direction ; for, as Miiller 

 had already pointed out, this name had been employed since 1821 to designate a section 

 of the Polyzoa established by Lamouroux. It is a pity, however, that Dujardin, instead 

 of limiting the application of Lamarck's name Comatula to the species of Miiller's sub- 

 genus Alecto, did not revert to the old name of Antedon, which was proposed by his 

 countryman De Freminville in 1811, and had since received but little notice. This step 

 was taken by Mr. Norman' a few years later. He did not, however, use Jntedoii as 

 precisely equivalent to Alecto, but applied the name to those forms only in which the 

 mouth is central and the anus lateral ; and he has been followed by nearly all the sub- 

 sequent writers upon the Crinoids. 



The etymology of Antedon is somewhat obscure. De Freminville described his typical 

 species as Antedon gorgonia, which gives no information as to the gender of the name. 

 Mr. Norman, however, arrived at the conclusion that it is masculine, and hence 

 described the common British species as Autedon rosaceus. In this respect all the later 

 writers have agreed with him with the exception of Pourtales ^ who cmi)loys Antedon 

 as a feminine name; and in this step he has since been justified by the result of the 

 recent etymological researches of Mr. Spedding ^ 



It will be used in the same manner in the following pages, both because this seems to 

 be etymologically correct, and for the sake of convenience ; since, as long as Miiller's 

 system of trinomial nomenclature is employed for the Comatula;, it is far simpler to 

 write Comatula (Antedon) rosacea than Antedon rosaceus= Comatula rosacea. In any 

 case, we are now acquainted with so many different types, Antedon, Actinometra, Co- 

 master, Phanogenia, and Ophiocrinus, to all of which Lamarck's designation Comatula 



' " On tlio Genera and Species of tho British Ecbinodermata," Ann. and JTag. Nat. Hist. ser. 3, vol. xv. p. 98. 

 ■ Bull, of the Mus. of Comp. Zool. vol. i. No. 6, " Contributions to the Fauna of the Gulf Stream at Great Depths," 

 p. Ill ; and No. 11, " List of tho Crinoids obtained on the Coasts of Florida and Cuba in 1867, 1868, 1869," p. 355. 

 ' • Nature,' vol. xv. p. 366. 



