19 



ered with smaller polygonal plates. Most of the sutures being 

 destroyed in our specimen, these plates are not indicated in the 

 illustrations. The vault is broken in our specimen so as to show- 

 no part of the subcentral proboscis. Two pores penetrate the 

 vault between each pair of arms, which gives to this species 

 twenty of these so-called ovarian apertures. 



This species is distinguished by its general form, flattened calyx, 

 ovate azygous area connected with the vault, regular distribution 

 of large convex plates on the vault, and twenty arms. It cannot 

 be mistaken for any species heretofore described. 



Found in the St. Louis Group, in Washington county, Indiana, 

 and now 7 in the collection of Wni. F. E. Gurley. 



BATOCRINUS BURKETI, n. Sp. 



Plate II, Fig. 9, showing column, calyx and arms, azygous view. 



This species is rather above medium size and is founded on a 

 single fine specimen on a slab. Of course, it does not disclose the 

 entire calyx and as the arms are preserved the vault cannot be 

 seen. The calyx is nearly twice as w T ide as high, and subhemi- 

 spherical. Though somewhat lobed in the superior part there are 

 no radial ridges or proper evidences of surface ornamentation. 

 The column is round, med"um size, and composed, within an inch 

 of the calyx, of rather thick plates, every alternate one projecting 

 beyond the other; but farther removed from the calyx, the pro- 

 jecting plates are at irregular distances from each other as shown 

 in the illustration. 



Basals form a low hexagonal cup, more than one-half wider than 

 the diameter of the column and bearing a small rim or truncated 

 bottom which contains the concave depression for the insertion of 

 the column. First primary radials large, a little wider than high, 

 three hexagonal, two heptagonal. Second primary radials rather 

 large and about one-half wider than high. Third primary radials 

 differ greatly in size, and part are pentagonal and others hexagonal. 

 The one on the left of the azygous area is only a little larger 

 than the second primary radial, pentagonal, axillary and bears on 

 one side three secondary radials, and on the other which adjoins 

 the azygous area one secondary radial which is axillary and sup- 

 ports on each upper sloping side two tertiary radials. The arms 

 then bifurcate on the third plate, which gives to this ray six 

 arms. The third primary radial on the right of the azygous area 

 is hexagonal, axillary and bears on the side adjoining the azygous 

 area two secondary radials, and on the distal side two secondary 



