CARBONIFEROUS AGE. 303 



P. Godonii Defr. (P. florealis, in part), — both from the Kaskaskia limestone; P. 

 Woodmani M. & W. Fig. 573, Poteriocrinus Missouriensis Shumard, from the St. Louis 

 limestone ; Fig. 574, Actinocrinus proboscidialis H. ; Fig. 575, Dorycrinus unicornis M. 

 & W.; Fig. 576, Zeacrinus eleyans H., — this and the two preceding from the Burling- 

 ton limestone; Fig. 577, Batocrinus Christyi'M. & W., the arms fallen off, — from the 

 Encrinal limestone of Missouri; Fig. 579, proboscis of Batocrinus lonyirostris H. ; Fig. 

 578, Platycrinus Siffordi Troost, side-view, from Burlington. Most of the above Cri- 

 noids have lost their arms and pedicels. The most proline locality of Crinoids, as yet 

 known, is Burlington, Iowa, where Mr. Charles Wachsmuth has collected three hundred 

 and fifty-five species, representing forty-four genera, besides six Echinoids, four Asteri- 

 oids, and one Ophiuroid. The Keokuk beds of Crawfordsville, Indiana, yield much 

 more numerous specimens, and in more nearly perfect condition; but less than fifty 

 species have yet been found there. The genera most numerously represented are Actin- 

 ocrinus (including several subgenera), Cyathocrinus, Dichocrinus, Forbesiocrinus, Pla-i 

 tycrinus, Poteriocrinus, Scaphiocrinus, and Zeacrinus. 



Echinoids. — Fig. 583, Archceocidaris Wortheni H., of the St. Louis limestone; Fig. 

 584, A. Shumardana H., of the St. Louis limestone, — a spine enlarged; Fig. 584a, 

 plate of the same species, enlarged about two diameters; Fig. 585, plate of Archceo- 

 cidaris Norwoodi H., natural size, from the Chester limestone. Fig. 587, Melonites mul- 

 tipora 0. & N., from the St. Louis limestone, the apical disc; 587 a, a portion of one of 

 the ambulacral series, enlarged two diameters; Fig. 586, Oliyoporus nobilis M. &. W., half 

 natural size, from the Burlington limestone ; Fig. 587 b, ambulacral plates of 0. Dance 

 M. & W., enlarged two diameters. Figures 586, 587, a, b, are from Worthen's Report 

 on the Geology and Paleontology of Illinois. The genus Archceocidaris, like the mod- 

 ern Cidaris, has large prominences on the plates, to support the spines, which are also 

 large. In Melonites and Palceechinus, the plates are without prominences, and the spines 

 small. 



3. Mollusks. — (a.) Bryozoans. — Fig. 590, Archimedes Wortheni H., being a 

 portion of the spiral axis, with the reticulated expansion removed. Fig. 589 a, a por- 

 tion of the reticulated expansion, magnified and showing the non-poriferous surface. 

 Fig. 589 b, the poriferous side of the same. 



(b.) Brachiopods. — Fig. 598, Chonetes ornata Shum. (natural size), from the Litho- 

 graphic and Chouteau limestones, Missouri; 598a, enlarged surface-markings of same; 

 Fig. 597, Spirifer biplicatus H., from Burlington and Quincy, Illinois; Sp. Keokuk H., 

 from the Keokuk beds; Fig. 591, Orthis Michelini Morr. (var. Burlinytonensis H. ), from 

 the Burlington limestone ; Hemipronites crenistria Dav. ( Orthis or Streptorhynchus um- 

 braculum) (Fig. 605); Fig. 592, Spiriferina octoplicata M. ; Fig. 593, Spirifer bisulcatus 

 Sow. (increbescens H.); Fig. 594, Retzia Verneuiliana H. ; Fig. 595, Chonetes variolata 

 D'Orb. ; Fig. 595 a, hinge- line of same, and aperture, closed by a pseudo-deltidium; 

 Fig. 596, Productus punctatus Mart. ; also P. Fleminyii Sow., P. eleyans N. & P., Spi- 

 rifer incrassatus Eichw., Sp. spinosus N. & P., from the Chester limestone, etc. Th3 

 Spirifer incrassatus is confined in Missouri to the lower Archimedes limestone. Many 

 of the other Brachiopods occur not only in the Subcarboniferous, but also in the Coal- 

 measures. They are common also in Europe. 



(c.) Lamellibranchs. — Nucula Shumardana H., N. nasuta H., Cypricardina Indian- 

 ercstsM., Conocardium Meekanum H., all from the St. Louis limestone of Indiana, Illi- 

 nois, and Idaho; Pinna Missouriensis Swallow, of the Chester limestone of Illinois; 

 species of Yoldin, Nuculann, Myalina, Schizodus, Aviculopecten. 



(d.) Pteropods. — Species of Bellerophon, Conularia, etc. 



(e.) Gasteropods. — Euomphalus Speryenensis H., Pleurotomaria Meekana H., and 

 many other species of these genera, as well as Platyceras, Straparollus, Naticopsis, Na- 

 tica, Bulimella, Loxonema, etc. 



(f.) Cephalopods. — The Cephalopods are of the genera Nautilus {N. spectabilis M. & 

 W., from the Chester, two feet in diameter), Orthoceras (0. nobile M. & W., from the 

 Chester, five to six feet long and one foot in diameter), Gyroctras (G. Burlinytonense 

 H., from Iowa, five inches in diameter), Goniatites, etc, 



