21 



Basals stand upright, and form a cup, about one-half wider 

 than the diameter of the column, having a height equal to 

 about one- third of the diameter, rather deeply notched at the 

 sutures and* having a hemispherical depression for the at- 

 tachment of the column. Columnar canal cinq uef oil. First 

 primary radials unequal in size, wider than long, three hex- 

 agonal, one heptagonal. Second primary radials four times as 

 wide as long, quadrangular. Third primary radials three or 

 four times as large as the second, pentagonal, axillary, and in 

 two of the rays support on each upper side two secondary ra- 

 dials, the last being axillary and supporting on each upper 

 side two tertiary radials, which gives to each of these rays 

 four arms. In the other two rays, one of which is on the left 

 of an azygous area and the other between the azygous areas, 

 there is on oue side of the third radials two secondary radials, 

 the last being axillary and supporting two tertiary radials, and 

 on the other side a secondary radial which is axillary and sup- 

 ports on one side two quaternary radials and upon the other 

 a tertiary radial which is axillary and supports two quaternary 

 radials, which arrangement gives to each of these rays five 

 arms. There are, therefore, eighteen arms in this species. 



In each of the two regular areas there are two plates, one 

 large followed by a smaller one! In one az}' r gous area there 

 are six plates and in the other seven. The first is in line with 

 the first primary radials and of about the same size. It is fol- 

 lowed, in the second range, by three plates and in the third 

 range by two plates in one area and three in the other. 



Vault convex and covered by tumid, polygonal plates and 

 bears a rather large subcentral proboscis. 



Found in the Burlington Group, at Burlington, Iowa, and 

 now in the collection of A. Albers, of Cincinnati. 



Remarks. —There have been described one hundred and 

 seventy-seven species of Batocrinus, from the Subcarboniferous 

 rocks of North America, and none from rocks higher or lower, 

 in the Geological scale, if we except Actinocrihiis praecursor, 

 Hall, from the Hamilton Group, which has been referred lo 

 DorycrimiF, by some authors, and may be a Baiocriims or be- 

 long to some other genus. It is certainly not an Actinoerimi?, 

 and we see no reason to think it is a Durycrinus, but the basal 

 and radial series are the same, as in Batocrinus. Of these one 



