224 



Cincinnati Society of Natural History. 



and each has a general obovate outline. This species, however, is dis- 

 tinguished, readily, by the numerous, smaller, intercalated plates, upon 

 the surface, which do not characterize H. pustulosus. 



Farther denning it, we ma} 7 sa} T , that it appears to have possessed a 

 small column. The lower range of plates consists of eight, which are 

 slightly longer than wide These are succeeded by a range of eight 

 plates, which are a little larger than those in the first range, and 

 each of which is longer than wide. This range is succeeded by 

 a number of small intercalated plates, which, in fig. 1, indicate 

 about eighteen plates in the circumference of the specimen, but one 

 side of the specimen is injured, so that only one half of them can be 

 distinguished, and if fig. la, as supposed, belongs to the same species, 

 and shows the opposite side, then some larger plates occur, and there 

 are less than eighteen thrown into an irregular range. Above this, 

 large plates may be described as surrounded with smaller ones, rather 

 than saving that they form ranges surrounding the body, though some 

 of the larger plates rest upon each other, aud form a line of plates of 

 irregular size, extending from the base to the summit, but not in the 

 opposite direction. 



The summit of each specimen is too much injured to allow any cer- 

 tainty in the determination of the mouth and ambulacral opening, 

 though the latter appears to have been quite central. 



The species is founded upon two specimens, each of which preserves 

 only one side. They are from the magnesian limestone, of the age of 

 the Niagara Group, at Joliet, Illinois, and belong to the collection of 

 W. C. Egan, of Chicago. Another specimen, in the same collection, in- 

 dicates a distinct species, with remarkably porous plates, but the 

 specimen is not in such a state of preservation as to justify giving to 

 it a specific name. 



EuCALYPTOCRIXUS PROBOSCIDALIS, 11. Sp. 



» t 



[Plate IX., fig. 2, natural size, as drawn from a plaster cast of the original.] 



The calyx of this species is elongated, and even when covered with 

 plates is longer than wide. With the brachials and interbrachial plates 

 attached, it is elongate-cylindrical, or possesses a length over two and 

 a half times its diameter, and above this the species bore a huge pro- 

 boscis, having a length almost equal to all the other parts of the body. 



The calyx, in the form and arrangement of the plates, is much like 

 E. egani, but is proportional!} 7 a little more elongated, and a little less 

 truncated at the base. 



