SHUMARD — CATALOGUE OP PALAEOZOIC FOSSILS. 387 



PLATYCRINUS (continued). 



Americanus, Owen & Shumard, 1852. Jour. Acad. Nat. Sci. Phil., 



2d ser., vol. ii., p. 89, pi. 11, fig. 1.— 1852. Geol. Iowa, 



Wise. & Minnes., p. 594, pi. v. B., fig. 1. — Platycrinus orno- 



granulus, McChesney. Pal. Foss., p. 3, pi. 5, fig. 8. — Enc. 



— Burlington, Iowa. 

 Ann Dixoni,* Troost, 1850. List Crin. Tenn., Proc. Amer. Assoc. 



Camb. Meet., p. 61. — Niag. — Decatur Co., Tennessee, 

 asper (Pleurocrinus), Meek & Worthen, 18G1. Proc. Ac. Nat. 



Sci. Phil., p. 129. — Enc. — Burlington, Iowa. 

 Burlino-tonensis, Owen & Shumard, 1850. Jour. Acad. Nat. Sci. 



Phil., 2d ser., vol.ii., p. 60, pi. 7, fig. 5.— 1852. Geol. Iowa, 



Wise. & Minn., p. 589, tab. 5 A., fig. 5. — Platycrinus %tor- 



natus, McChesney. Pal. Foss., p. 6, pi. 4, fig. ^ — Erk. — 



Burlington, Iowa. ™ 



brevinodus, Hall, 1861. Des. New Crinoidea, Prelim. Not., p. 4. 



— Bost. Jour. Nat. Hist., vol. vii., p. 286. — Arch. — Keokuk, 



Iowa, 

 calyculus, Hall, 1861. Des. New Crin., Prelim. Not., p. 16.— 



Enc. — Burlington, Iowa, 

 canaliculars, Hall, 1858. Geol. Iowa, vol. i., pt. 2, p. 539. — Enc. 



— Burlington, Iowa, 

 cavus, Hall, 1858. Geol. Iowa, vol. i., pt. 2, p. 527, pi. 8, fig. 1.— 



Enc. — Burlington, Iowa, 

 contritus, Hall, 1863. Crin. Wav. Sands. Ohio, p. 5. — Chem. — 



Summit Co., Ohio, 

 clytis, Hall, 1861. Des. New Crin., Prelim. Not., p. 4.— Boston 



Nat. Hist., vol. 7, p. 285. — Enc. — Burlington, Iowa. 

 corrugatus, Owen & Shumard, 1850. Jour. Acad. Nat. Sci. Phil., 



2d ser., vol. ii., p. 59, pi. 7, fig. 2.— 1852. Geol. Iowa, Wis. 



&Minn., p. 589, pi. v. A., fig. 2. — Enc. — Burlington, Iowa, 

 depressus,* Owen, 1843. Cat. Geol. Form. Ohio Val., No. 279. 



— Kas.^) — Monroe Co., Indiana. 



less elongated, central or suhcentral proboscis, bearing the opening on one 

 side near tbe upper extremity. 



Type. — P. Icevis, Miller. — Also includes P. spinosus and P. 30-dactylus, 

 Austin, P. Mullerianus, Koninck, and P. r/ranvlatvs, Miller. 

 "2. Centrocrinus, Austin — Opening of summit nearly or quite central, 

 but not elevated upon a proboscis. 



Type. — P. [Centrocr.] gigas } Gilbertson. 

 " 3. Cupellcccrinus, Troost. — Differs from tbe last only in having its sec- 

 ond radial pieces merely rudimentary, or so small as to allow the first bra- 

 chials to rest partly upon the first radials. 

 Type. — P. Tennesseensis, Roemer. 

 "4. Pleurocrinus, Austin. — Differs from Centrocrinvs only in having the 

 opening of the summit lateral and nearly or quite on a line with the arm 

 bases. 



Examples. — P. [Pleurocr.'] mucronatits, Austin ; P. \Pleurorr.'] tuber- 

 culatus, Miller; P. \Pleurocr.~] tuberosvs and P. [Plevroer.] subspino- 

 sus, Hall, and P. [Pleurocr.'] asper, Meek & Worthen." 

 There can be no doubt as to the utility of a separation such as is here 

 proposed, but unfortunately the upper part of the body has not been dis- 

 covered in a large proportion of the described species, and therefore until 

 larger and more perfect collections are accessible to the student it will be 

 impossible to distribute all of the known species in their proper sections. 



