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



No further definitiou of Chladocrinus was ever given by Prof. L. Agassiz ; and it is 

 not surprising therefore that the genus has never been accepted by naturalists. The 

 remaining type which is supposed to be generically distinct from PentacHnus, is the 

 Cainocrinus of Forbes.^ It has recently been revived by de Loriol ; " but since it was 

 based on a misconception, and its only distinctive character depends upon a feature 

 which is very variable among the recent species, viz., the presence or absence of a closed 

 ring of basals, I see no good in retaining it (see pp. 281-283). Practically, therefore, 

 owing to the well marked characters of Extracrinus and our want of knowledge of 

 Balanocrinus, a definition of Pentacrinus for the study of recent forrtis need only 

 emphasise those points in which it diifers from Metacrinus. I have, however, referred 

 to one or two characters in which the genus differs from Extracrinus. 



Genus Pentacrinus, Miller, 1821.^ 



176L Palmier marln, Guettard, Memoires de Mathematique et de Physique tir^s des Eegistres derAcademie 



Eoyale des Sciences, de I'annee MDCCLV., Paris, 1761, p. 225. 



1762. Encrinus, Ellis, Phil. Trans., vol. lii. pt. i. for the year 1761, London, 1762, p. 35S. 



1766. Isis, Linnaeus, Systenia Natural, ed. xii., Holmiffi, 1766, t. i. p. 1288. 



1816. Encrinus, Lamarck, Histoire Naturelle des Animaux sans Vertebras, t. ii., Paris, 1816, p. 432. 



1820. Pentacrinites, von Sehlotheim, Die Petrefactenkunde, Gotha, 1820, p. 327. 



1821. Pentacrinus, Miller, A Natural History of the Crinoidea, Bristol, 1821, p. 45. 

 1832. Pentacrinites, Goldfuss, Petrefacta Germaniae, Dusseldorf, 1832, t. i. p. 168. 

 1832. Solanocrinites, Goldfuss, Ibid., p. 168. 



1834. Pentacrinus, de BlainvOle, Manuel d'Actinologie, Paris, 1834, p. 257. 



1834. Encrinus, de Blainville, Ibid., p. 254. 



1835. Pentacrinus, Agassiz, M^m. de la Soc. d. Sci. Nat. de Neuchatel, t. i. p. 194. 



1835. Chladocrinus, Agassiz, Ibid., p. 195. 



1836. Pentacrinus, Buckland, Geology and Mineralogy, London, 1836, vol i. p. 432. 



1837. Isocrinus, von Meyer, Museum Senckeubergianum, Frankfurt, ii. p. 251. 



1843. Pentacrinus, MliUer, Abhandl. d. k. Akad. d. Wiss. Berlin, Jahrg. 1841, p. 177. 



1845. Pentacrinus, Austin, A Monograph on Eecent and Fossil Crinoidea, Bristol, 1843-45, p. 110. 



1845. Pentacrinus, Desor, Bull Soc. d. Sci. Nat. de Neuchatel, vol. i. pp. 213, 214. 



1845. Isocrinus, Desor {non von Meyer), Ibid., p. 213. 



1845. Balanocrinus, Agassiz {non de Loriol), in Desor, Ibid., p. 214. 



1847. Pentacrinus, d'Orbigny, Cours element, de Paliiontol. et de Geol. stratigr., t. ii. Fasc. 1, Paris, 1852, 



p. 149. 

 1852. Isocrinus, d'Orbigny, Ibid., p. 149. 



' British Tertiary Echinoderms, p. 33. ° Swiss Crinoids, pp. Ill, 112. 



5 The above Ust contains, I believe, all the most important references to the recent Pentacrinus since the time of 

 Guettard, together with notices of the chief pateontological works in which this type and its fossil representatives 

 are mentioned. But it makes no pretence whatever of recording all the various names which have been bestowed at 

 dififerent times upon fragments of fossil Pentacrinidae. A task of this kind is scarcely worth undertaking, as the result 

 would be totally incommensurate with the labour involved. 



