37 



if that genus is worth retaining, which may be doubtful. They have no 

 resemblance to Amphoracrinus, which is a genus having a quadran- 

 gular second primary radial, which allies the calyx to Batocrinus, 

 and which has a ponderous high vault and large proboscis. Xo true 

 Amphoracrinus, as represented by the type, A. gilbertsoni, or the 

 allied species, A. atlas, has ever been found in America, and probably 

 all American species that have been referred to A mphoracrinus belong 

 to Actinocrinus. 



Found by R. A. Blair, in the Chouteau limestone, at Sedalia, Mis- 

 souri, and now in the collection of S. A. Miller. 



Family DOLATOCRINID^. 



DOLATOCRINUS NEGLECTUS, 11. Sp. 



Plate II, Fig. 27, basal view; Fig. 28; summit; Fig. 29, side view. 



Species full medium size. Calyx low, basin shaped, a little more 

 than three times as wide as high, broadly and deeply concave below, 

 the depression including the second radials, and having a deep 

 funnel-shaped columnar pit which is bounded by a pentagonal rim. 

 The angles of the pentagon unite with the radial ridges, and the fun- 

 nel within the rim is smooth or without ornamentation and extends 

 as high as the top of the calyx. Radial ridges within the concavity, 

 angular elevations, but above, they are broken into elongated angu- 

 lar nodes by the sutures between the plates. The surface of the in- 

 terradial areas is radiately sculptured from a central pit, instead of 

 from a central node; and other parts of the calyx are irregularly 

 sculptured. Column round and attached at the bottom of the funnel- 

 shaped columnar pit. 



Basals form a round cup deeply inserted in the calyx where they 

 rise as high as the top of the calyx. The mouth of the cup is about 

 one-third wider than the diameter of the column. First primary 

 radials as long as wide, smooth below the pentagonal rim and sculp- 

 tured above it. Second primary radials twice as wide as long, quad- 

 rangular. Third rnimary radials larger than the second, pentagonal 

 axillary, and, in each of four of the rays, bears upon one upper slop- 

 ing side four secondary radials, and upon the other a single sec- 

 ondary radial which is axillary and supports on each upper side 

 three tertiary radials, which arrangement gives to each of these rays 

 three arms. In the other ray, the third primary radial bears upon 



