BATOCRINIDiE. 



435 



them the interbrachials are continuous with the interambulacral plates. 

 Agaiu Batocrinus has well defined, large respiratory pores, which are ap- 

 parently unrepresented in Lobocrimts. 



Lobocrinus Nashvillse (Tkoost). 

 Plate XXXI. Fig. 1. 



1849. Adinoermus if«j/;K7fe — Troost ; Catal. of Criuoidea (Proceed. Araer. Assoc, for Adv. Sci„ 184<!, 

 p. 60). , 



1858. AclinocHmis Nashville -n^W; Geol. Rep. Iowa, Vol. I., Part IL, p. 609, Plate 15, Fig. 4, and 

 Plate 16, Figs, ia, b. 



1873. Batocriims Nashdlla — M. aud W. ; Geol. Rep. Illiuois, Vol. V., p. 368. 



1881. Batocrinus NashviUce — W. and Sp. ; Revisioa Palaiocr., Part II., p. 167 (Proceed. Acad. Nat. Sci. 

 Pbila., p. 311). 



1885. Adinocrims Naslimllm — Quenstedt ; Haiidb. der Petrefactenkunde, Plate 77, Fig. 2. 



1890. Batocrinus NashvilU — Worthen ; Geol. Rep. lUiiiois, Vol. VIII., p. 85, Plate 13, Fig. 5. 



Calyx higher than wide, urn-shaped, truncated at the base, the lower 

 edge somewhat projecting laterally and rounded off. Dorsal cup higher 

 than the ventral disk, distinctly lobed at the arm regions, contracted at the 

 basi-radial suture, whence it spreads at first gradually, and then rapidly, to 

 the arm bases, which form a projecting rim around the calyx. Plates moder- 

 ately convex, without ornamentation ; the suture lines distinct. 



Basals large, forming a subcylindrical cup almost twice as wide as high ; 

 the interbasal sutures slightly indented. Eadials large, generally wider than 

 long, their median portions raised into a transverse tubercle. Costals one 

 third the size of the radials, a little wider than long ; the first quadrangular, 

 the second pentangular. Distichals 2X10; followed by 1X20 palmars, 

 which project upward and outward, and support the arms. Arm facets 

 directed upwards. Arms twenty; arranged in pairs, with deep depressions 

 between the rays, and smaller ones between their main divisions. Inter- 

 brachials : 1, 2, 2, 2, the last two resting between the arm bases. Anal plate, 

 as a rule, a little higher than the radials ; succeeded by three rows of three 

 plates each. Interdistichals one, resting between the second distichals. 

 Orals and radial dome plates — the latter of a first and second order — 

 more or less highly convex, contrasting considerably with the small supple- 

 mentary pieces surrounding them, which are quite numerous near the arm 

 bases. Anal tube strong, almost central ; compo.sed of large tumid plates, 

 which gradually decrease in size upwards. At a height of an inch and a half 

 from the base, the tube has a ring of five spiniferous plates, the spines some- 

 times nearly an inch long, and directed horizontally. Column stout, and, so 



