10 ROBERT TRACY JACKSON ON ECHINI. 



Of those who have published on Palaeozoic Echini, the most important are as follows. 

 M 'Coy did pioneer work; in 1844 he published several species of Palaeechinus, the first known, 

 also species of Archaeocidaris, and later, Perischodomus. James Hall described several new 

 species of Archaeocidaris, also Lepidechinus. Meek and Worthen, or Meek independently 

 in a few cases, did most accurate and painstaking work, describing many genera and species 

 with a care and faithfulness that have rarely been equalled by investigators of these ancient 

 and difficult fossils. Sir Wyville Thomson described the remarkable Echinocystites. Baily 

 published observations on Palaeechinus and described Perischocidaris harteiana. Schmidt 

 made important studies of Bothriocidaris, describing a new species. Keeping described new 

 species and published good figures of old species. Duncan made studies of the ambulacrum 

 in species of the Palaeechinidae. C. A. White described a number of new species of Archaeo- 

 cidaris and a Lepidesthes. Keyes described a new species of Oligoporus, published a number 

 of new figures, and gave a revision of the American species. Jaekel published a careful study 

 of a species of Bothriocidaris. Jackson and Jaggar published a detailed study of Melonechinus 

 multiporus, and Jackson a general study of Palaeozoic Echini, described a few new species, and 

 made an attempt at a natural classification. Julien described new species and figured others 

 from the Carboniferous of France; his material was evidently not very good as shown by the 

 photographic illustrations. Tornquist made a careful study of German species with most 

 excellent figures; he described a number of new species and genera and gave a classification. 

 Miss Klem published a revision of Palaeozoic Echini with a synopsis of known species. Her 

 bibliography and synonymies are very full and most helpful, but unfortunately there are many 

 errors in the text, so that statements need verification. Fraipont published an interesting series 

 of species from the Carboniferous of Belgium. 



Besides the above, new species or genera of Palaeozoic Echini or observations on specimens 

 have been published by many authors. Aldrovandus, in 1618, published the first Palaeozoic 

 echinoid that has been discovered in the literature. He figured at this early date a specimen of 

 Bothriocidaris globulus under the caption, "Echinus lapis spoliatus a spinis." It is extraordinary 

 that this especially rare type should have been so early discovered. De Koninck, Miinster, 

 L. Agassiz, Norwood and Owen, Fischer von Waldheim, Forbes, Geinitz, King, Roemer, J. 

 Miiller, and Sandberger published species and genera with more or less full descriptions of 

 the same. Desor published some new forms and gave a revision of the then known Palaeozoic 

 species. Young, Wright, Shumard, Schultze, and Safford published a few types, some of 

 much importance. Loven in his "Etudes" gave a revision of the then known species, but 

 apparently without observations on specimens. A. Agassiz in the "Revision" (1872-74, 

 p. 644-650) gives a general discussion of Palaeozoic Echini and in several other monographs 

 has published observations on the group and some discussions of the observations of others. 

 Stache, Miller, and Schliiter published new species. Zittel in his text-book introduced new 



