CLASS I ECHINOIDEA 257 



it is doubtful whether it may not be quite as properly assigned to one of 

 several other genera. Other Jurassic and Cretaceous forms have been 

 assigned by Liitken to Ophmra Lamk. (Ophioglypha Lym.), and there is good 

 reason to believe that the genus, in a broad sense, is one of the oldest now 

 living. Fossil Ophiurans, whose disk-covering or mouth parts cannot be 

 determined, ought not to be assigned to Recent genera, but all such and all 

 others which cannot be accurately characterised may well be designated by 

 the broad term Ophiurites. 



[The text for the foi-egoing section on Asterozoa has been revised for the present work 

 by Dr. Hubert Lyman Clark, of the Harvard Museum of Comparative Zoology, at Cambridge, 

 Massachusetts. — Edito ii. ] 



SuBPHYLUM C. Echinozoa Leuckart. 



Armless and non-pedunculate Echinodermata, with glohdar, cordiform, discoidal 

 or worm-like bodies, which are either encased in a plated test or are invested with a 

 leathery integument, embedded within which are small-sized detached calcareous bodies. 



Class 1. ECHINOIDEA Bronn. Sea-Urchins.i 



Animals possessing a wide range of structure, but hating alimentary, reproductive, 

 nerve and water vascular systems within an enclosing superficial pentamerous plated 

 skeleton, which bears movable spines. There are from two to twenty columns of plates 

 in each of the five ambulacral areas, and from one to fourteen columns of plates in 



1 Literature : Agassiz, L., and JJesor, £., Description des echinides fossiles de la Stiisse, 1839- 

 1840. — Catalogue raisonne des families, genres, et des especes de la classe des echinides. Ann. des 

 Sci. Nat., 1846-47. — d'Orbign//, A., Paleontologie fran^aise. Terrains cretaces 1853-55, vol. vi. — 

 Cotteau, G. II., and Triger, Echinides du departement de la Sarthe, 1857. — Desor, E., Synopsis 

 des echinides fossiles. Paris, 1858. — Wright, T., Monograph on the British fossil Echinodermata 

 of the Oolitic Formations. Palaeontograph. Soc, 1857-78. — Idem, Cretaceous Formations. Palaeont. 

 Soc, 1864-82. — Cotteau, G., Paleontologie fran9aise, vols. vii. , ix. andx., 1862-79.— Lmibe, G. C, 

 Echiuodermen des viceutischen Tertiiirgebietes. Deukschr. Akad. Wiss. Wien, vol. xxix., 1868. 

 — Loriol, P. de, and Desor, E., Echinologie helvetique, vols, i.-iii. Geneva, 1868-85. — Quenstedt, 

 F. A., Petrefractenkunde Deutschlands (vol. iii., Echiniden), 1872-75. — Agassiz, A., Revision of 

 the Echini. 111. Cat. Museum Comp. Zool. Cambridge, No. 7, 1872-74. — Reports on the Echini 

 of the Hassler (1874), Challenger (1881) and Blake (1883) ExiJeditions. — Zow'm, S., Etudes sur les 

 echinoidees. Sveusk. Vetensk. Akad. Haudl., vol. xi., 1874. — Cotteau, Peron, and Gauthier, 

 Echinides fossiles de I'Algerie. Paris, 1876-91. — Loriol, P. de, Monographic paleontologique, etc. 

 Abhandl. Schweiz. Pal. Gesellsch., 1876-81, vols, iii., viii. — Dames, W., Die Echiniden der 

 viceutischen vmd verouischen Tertiar-Ablagerungen. Palaeontographica, 1877, vol. xxv. — Agassiz, 

 A., Palaeontological and Embryological Development. Proc. Amer. Assoc. Adv. Sci., 1880. 

 — Duncan, P. M., and Sladen, W. P., Monograph of the fossil Echinoidea of Western Sind. 

 Palaeont. Indica, Ser. xiv., 1882-84.- — Scklilter, C, Die reguliiren Echiniden der norddeutschen 

 Kreide. Abhandl. zur geolog. Special-Karte von Preussen, vol. iv., 1883. — Idem, Neue Folge, 

 Heft 5, 1892. — Loriol, P. de, Descrij^tiou des echinides. Commission des travaux gcol. du Portugal, 

 1887-88, vol. ii. — Loven, S., On Pourtalesia. Sven.sk. Vetensk. Akad. Haudl., 1884, voL xix. — 

 Pomel, N. A., Classification methodique et genera des echinides vivantes et fossiles, 1883. — Duncan, 

 P. M., Revision of the Genera and Great Groups of the Echuioidea. Journ. Linn. Soc, 1889, 

 vol. xxiii. — Loven, S., Echiuologica. Bihaug till Svensk. Vetensk. Akad. Haudl., 1892, vol. 

 xviii. — Clark, W. B., Mesozoic Echinodermata of the United States. Bull. U.S. Geol. Survey, 

 No. 97, 1893. — Tornquist, A., Das fossilfiihrende Untercarbon am ostlichen Rossbergmassiv 

 iu den Siidvogesen, iii., Beschreibung der Echiniden-Fauna. Abhandl. Geol. Special-Karte Elsass- 

 Lothringen, 1897, vol. v. — Morteusen, T., Siam Echinoidea. Danske Vidensk. Selsk. Skrift., 

 1904, vol. i. — Bather, F. A., Triassic Echinoderms of Bakony. Resultate der wiss. Erforsch. Bala- 

 tousees, 1909, vol. i. — Lambert, J. and Thiery, P., Essai de nomenclature raisonne des echinides. 

 Chaumont, 1909-12. — Jackson, R. T., Phylogeny of the Echini. Mem. Boston Soc. Nat. Hist., 

 1912, vol. vii. — Hawkins, II. L., Classification of the Holectypoida, etc. Proc. Zool. Soc. 

 London, 1912. 



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