380 THE CEINOIDEA CAMERATA OF NORTH AMERICA. 



rows of obscure nodes. Interbrachial plates three, consisting of a large tumid 

 plate, followed by two small, slightly convex pieces, above which the three 

 rows of palmars meet those from adjoining rays, except at the posterior side, 

 where only the plates of the upper row are in contact. Anal plate longer 

 than the radials ; followed by three and three plates. Ventral disk de- 

 pressed, greatly inflated above the arm bases ; composed almost exclusively 

 of the orals and radial dome plates, which are nodose. Anal tube compara- 

 tively slender at the bottom, formed of convex, elongate pieces ; its length 

 not known. 



Hoj'izoji and Locality. — Lower Burlington limestone ; Burlington, Iowa. 



Types in the collection of Wachsmuth and Springer. 



Remarks. — This species in the construction of the calyx is closely allied 

 to Baiocrinus pistillus, and in the arm structure resembles some species of 

 Ereimocrinus. 



Batocrinus clypeatus (Hall). 



Plate XXVII. Figs. 8a-e. 



I860. Actinocrinus di/peatus — Hall ; Suppl. Geol. Rep. Iowa, p. 12, Plate 3, Fig. 12. 



1867. Actinocrinus (Batocr.) cli/petilus — Meek and Worthen ; Geol. Rep. Illinois, Vol. II., p. 150. 



1881. Stttocriims clypeatus — VV. and Sp, ; Revision Palseocr., Part II., p. 166. 



Sjn. Actinocrinus papillatus — Hall; Suppl. Geol. Rep. Iowa, p. 29, Photogr. plates (1S72), Plate 



iA, Figs. 10 and 11. 

 Sjn. Batocrinus papillatus — Meek and Woethen; Geol. Rep. Illinois, Vol. V., p. 367. 

 Syn. Acti?iocriuus inornatus — Hall ; Suppl. Geol. Rep. Iowa, p. 24. 

 Sjn. Batocrinus inornatus — Meek and TTorthen ; Geol. Rep. Illinois, Vol. V., p. 367 ; and 



Wliitaeld, Mem. Anier Mus. Nat. Hist., 1893, Vol. I., p. 15, Plate 2, Figs. 1-3. 

 Sya. Batocrinus comparilis — S. A. Miller, 1892 ; Adv. Sheets IStli Rep. Geol. Surv. lud., p. 32, 



Plate 5, Figs. 18 to 20. 

 Syn. Batocrinus aspratitis Miller and Gueley, 1894 ; Geol. Surv. Illinois, Bull. 3, Plate 6, Figs. 

 4, 5, 6. 



A very variable species. Calyx a little wider than long ; the dorsal cup 

 higher than the ventral disk, convex at the base, the sides concave. Plates 

 from almost flat to moderately convex. 



Basals very small, in some cases invisible in a side view. Eadials more 

 prominent than any of the other plates, their median portions more or less 

 tumid; they are wider than long and concave at the upper face. Costals 

 quadrangular and pentangular, both together smaller than the radials ; the 

 first smaller than the second. Disticlials two, as large as the costals, each one 

 supporting 2x2 palmars, which are in contact laterally and support the free 

 arms. Arm openings twenty, arranged at almost equal distances, the intei'- 

 spaces slightly grooved. Arms very short, composed of two series of short 



