248 PROCEEDINGS OF THE ACADEMY OF [1881. 



1858. PI. pileiformis Hall. (Pleuroorinus.) Geol. Rep. Iowa, i, Pt. ii, p. 629, PI. 8, 

 figs. ;? a, b, c. Lower Burlington limest. Burlington, Iowa. This species 

 is easily distinguished from the other species with smooth plates, by having 

 only four arms to the ray. 



1850. PI. planus Ow. and Sh. Jour. Acad. Nat. Sci. Phila. (Ser. ii), vol. ii, p. 57 ; 

 also, 1852, U. S. Geol. Surv. Iowa, Wis. and Minn., p. 687, PI. 5 A, fig.s. 4 a, 

 c (not b, nor Geol. Rep. 111., iii, PI. 16, fig. 6, which are both PI. Pratteni 

 Worthen; nor Geol. Rep. Iowa, i, Pt. ii, PI. 8, figs. 6 a, b, which are PI. 

 Halli Shum.); Geol. Rep. 111., v, PI. 3, fig. 5. Lower Burlington limest. 

 Burlington, Iowa. 



1860. PI. plenus Meek and Worthen. Proc. Acad. Nat. Sci. Phila., p. 380 ; also 

 Geol. Rep. 111., ii, p. 267, PI. 20, fig. 3. Warsaw limest. Hardin Co., 111. 



1858. PI. pocilliformis Hall. (Pleuroorinus.) Geol. Rep. Iowa, i, Pt. ii, p. 528, 

 PI. 8, figs. 2 a, b. Lower Burlington limest. Burlington, Iowa. 

 Syn. PL verruoosus White, 1863. Bost. Jour. Nat. Hist., p. 602. 



1878. PI praenuntius Wachsm. and Spr. Proc. Acad. Nat. Sci. Phila., p. 249, PI. 

 2, figs. 1, 2. Upper Burlington limest. Burlington, Iowa. 



1860. PI. Prattenanus Meek and Worthen. Proc. Acad. Nat. Sci. Phila., p. 379 ; 

 also Geol. Rep. Ill, ii, p. 264, PI. 20, fig. 2. St. Louis limest. Randolph 

 Co., 111. 



1860. PI. Pratteni Worthen. Trans. Acad. Sci. St. Louis, p. 569 ; Meek and 

 Worthen, PL planus. Geol. Rep. 111., iii, p. 469, PI. 16, fig. 6. Lower Bur- 

 lington limest. Burlington, Iowa. 

 Meek did not consider PL Pratteni distinct from PL planus, and Owen and 

 Shumard seem to have been of the same opinion, for they figure in the U. S. 

 Rt-p. Iowa, Wis. and Minn., PI. 5 A, fig. 46 (not 4 a, e) a specimen, evidently 

 of the former type, under the latter name. 



1860. PL pumilus Hall. Supp. Geol. Rep. Iowa, p. 82, PI. 1, fig. 6. Warsaw 



limest. Warsaw, 111. 

 1844. PL punctatus McCoy. Carb. Foss. Ireland, p. 177, PL 25, figs. 15, 17. 



Mount, limest. Ireland. 

 1862. PI, quinquenodus White. (Pleuroorinus.) Proc. Bost. Soc. Nat. Hist., ix, p. 



18. Upper Burlington limest. Burlington, Iowa. 



1861. PL regalis Hall. Desc. New Sp. Crin., p. 16, Separate Photog. Plate 2, fig. 



6. Lower Burlington limest. Burlington, Iowa. 

 Syn. PL Oweni Meek and Worthen, 1861. Proc. Philad. Acad., p. 129. 

 1875. PL richfieldensis Hall. Geol. Rep. Ohio, Pal. ii, p. 167, PI. 11, fig. 4. 



Waverly gr. Ptichfield, 0. 

 1821. PL rugOSUS Miller (not Qoldf. = StorthingocrinvB Schultze). Hist. Cri- 



noidea, p. 79, with plate. Figured by Cumberland in Trans. Geol. Soc, vol. 



V, PL 5, fig. 10; Phillips, 1836, Geol. of Yorkshire, p. 204, PI. 2, fig. 20; 



Austin, 1842, Ann. and Mag. Nat. Hist., x, p. 109; Blainville, 1843, Man. 



d'Actin., PL 29, fig. 4; Austin, 1843, Mon. Rec. and Foss. Crin., p. 40, PI. 



4, figs. 2d-k; McCoy, 1844, Carb. Foss. Ireland, p. 177. Mount, limest. 



Caldy Island, Wales, also Mendip Hills, England. 

 1858. PL SaflEbrdi Hall. Geol. Rep. Iowa, i, Pt. ii, p. 634, PI. 18, figs. 5, 6. Lower 



part Keokuk limest. Nauvoo and Hamilton, 111., and Keokuk, Iowa. Prob- 

 ably Syn. of PL sonlptus. 

 1858. PL Sarae Hall. Geol. Rep. Iowa, i, Pt. ii, p. 673, PL 17, fig. 4. St. Louis 



limest. St. Louis, Mo. 



