450 THE CRINOIDEA CAMERATA OF NORTH AMERICA. 
the anterior side the base of the ventral tube, which is almost central, and 
more slender than usual in this genus. 
Horizon and Locality. — Lower Burlington limestone; Burlington, Iowa. 
Type in the (Worthen) Illinois State collection, Springfield. 
Remarks. —The specimen from which Hall made his description was 
defective, and the arm formula which he gives of the species is incorrect. 
It has normally but fourteen arms: 5,3; but when an additional arm 1s intro- 
duced, which is quite often the case, this is placed in the antero-lateral rays, 
and not in the posterior one. Hall gave the arm formula as #3, 
Macrocrinus verneuilianus (Suvum.). 
Plate XXX. Figs. 15, 16, 17, 18. 
1855. Actinocrinus verneuilianus —SuvuMaRd; Geol. Surv. of Missouri by Swallow, Part II, p. 1933, 
Plate A, Figs. la, . 
1873. Batocrinus verneuilianus Murx and WortHEN; Geol. Rep. Illinois, Vol. V., p. 379, Plate 4, Figs. 3 
1881. eee, verneuilianus — W. and Sp.; Revision Paleocr., Part II., p. 173 (Proceed. Acad. Nat. 
Sci. Phila., p. 347). 
1890. Evetmocrinus verneuilianus —S. A. Mrttnr; North Amer. Geol. and Paleont., p. 243. 
Calyx biturbinate, higher than wide; the dorsal cup higher than the 
ventral disk, truncate at the base, its sides a little concave, the arm-bearing 
plates projecting. Surface of plates flat or very slightly convex, the radials 
and first interbrachials always more or less elevated at the median portions. 
Basals rather large, forming a hexagonal cup with erect sides; grooved 
at the interbasal sutures; the column facet deep and narrow, occupying but 
one third the diameter at the bottom of the calyx. Radials twice as large 
as the two costals together, somewhat variable in form, but generally as long 
as wide, and the lateral faces considerably longer than the upper sloping 
faces; the two heptagonal plates larger than the hexagonal ones. First 
costals quadrangular, very small, twice as wide as long; the second some- 
what larger and pentangular. Distichals two in both divisions of the anterior 
ray, and also in one division of the other rays; the other division has but 
one distichal, which is axillary, and supports 2X 2 small palmars; there 
being normally fourteen arms, with variations from fourteen to eighteen, 
First palmars in lateral contact with each other and with adjoining dis- 
tichals, except at the anal side; while the upper plates meet only their 
fellows of the same ray, being entirely free at one side. Arm openings 
directed slightly upwards; the interspace between the posterior rays wider 
Tn 
