242 ECHINODERMATA— rELMATOZOA phylum iv 



While the great majority of Eecent stalked forms are deep-sea inhabitants, 

 the Paleozoic, on the contrary, often characterise shallow water deposits, and 

 are especially numerous in the vicinity of fossil coral reefs. Of the Mesozoic 

 Crinoids, the Eugeniacrinidae and Plicatocrinidae, whose remains are commonly 

 associated with those of Hexactinellid and Lithistid Sponges, probably lived 

 at considerable depths ; while, on the other hand, the Encrininae, Apiocri- 

 nidae, Saccocomidae and Holopidae, were undoubtedly shallow water forms. 



Crinoidal fragments have been detected in the Cambrian, but consist of 

 stem-joints only. The Ordovician of England also yields a variety of stem- 

 joints, and well-preserved calices of Hyhocrinus and Baerocrinus occur in rocks 

 of the same age in the vicinity of St. Petersburg. In North America, the 

 Trenton and Hudson River limestones are locally very rich in Crinoid 

 remains. The Silurian localities of Dudley, England, and especially the 

 island of Gotland, Sweden, are famous for the surprising abundance and 

 exquisite state of preservation of their fossil Crinoids. The Swedish 

 forms alone comprise forty-three genera and 176 species. The Silurian 

 of North America, notably the Niagara Group, likewise contains a large 

 variety of forms, many genera being identical with those of England and 

 Gotland. 



The best -known Devonian localities are the Eifel, Ehineland ; Nassau, 

 Westphalia ; the Ardennes and Department of Mayenne, France ; the Asturias, 

 Spain ; and New York, Michigan, and the region about the Falls of the 

 Ohio River, in North America. The Lower Carboniferous Limestone of Tournay 

 and Vise, Belgium, and that of England, Ireland, and the vicinity of Moscow, 

 Russia, are occasionally charged with exceptionally well-preserved crinoidal 

 remains. But the most famous of all horizons is the Lower Carboniferous 

 Limestone of North America, where in particular the localities of Burlington, 

 Iowa, and Crawfordsville, Indiana, have acquired a world-wide celebrity. 



The Upper Carboniferous contains large areas of crinoidal limestone, but 

 well-preserved specimens occur rarely, the most notable being at Kansas City, 

 Missouri ; some interesting forms from that horizon are found in Australia. 

 The Permian has yielded but a few genera, and those, so far as yet known, 

 belong to the Inadunata. A remarkable Crinoid fauna of this age has also 

 been discovered in the Island of Timor. 



^'-From the Trias only the Encrininae and a few species of Pentacrinus are 

 as yet known. The remaining members of the Articulata make their appear- 

 ance in the Jura and Cretaceous, and with the exception of the Eugenia- 

 crinidae and the Saccocomidae, the families are still represented in the existing 

 fauna. 



[The text for the entire subphylum Pelmatozoa has been revised by Mr. Frank Springer 

 of East Las Vegas, New Mexico, and Washington, D.C. The treatment of the classes Cystoidea 

 and Blastoidea is substantially the same as in the former edition of this work, but tliat of the 

 Crinoidea reflects the great progress in onr knowledge of this group that has been made 

 during the past decade. In that part of the revision which deals with post- Paleozoic Crinoids 

 Mr. Springer and Mr. Austin Hobart Clark, of the United States National Museum at 

 Washington, have co-operated with a view toward making the new knowledge of later and 

 Recent Crinoids more generally available for paleontologists. Lack of space alone prevented 

 a more detailed discussion of Recent Comatulids, such as had been actually jjrepared 

 for the present work by Mr. Clark. The student is therefore referred to the independent 

 publications of these two well-known echinodermologists. — Editoh.] 



