OWEN AND SHUMARD'S FOSSIL CRINOIDEA. 63 



Formation and Localities. — Occurs at Burlington in the encrinital layers of the 

 carboniferous limestone, immediately above the oolitic members. It is not an 

 abundant species. 



Genus CYATHOCRINUS, MUler. 



CyATHocRiNUs lowENsis. (New sp ) 



PI. 7, fig. 11, a, h, c. 



Body globose. Basal plate rather small, pentagonal, composed of five plates, 

 closely adhering among themselves, flattened, with a small hemispherical cavity for 

 the insertion of the column, having a small round perforation in the centre ; superior 

 angles bent slightly upwards. First series of perisomic plates five, of which four are 

 pentagonal, inclining, however, to a subhexagonal form ; and one hexagonal. These 

 plates are somewhat massive and tumid in their centres. The second series is 

 composed of six plates, five are pentagonal, support the arms and rest on the oblique 

 upper edges of the first series ; the sixth, which is hexagonal, is placed on the 

 superior truncated edge of the hexagonal plate of the first series, and supports on its 

 upper edges three small irregular plates. The articular facets for the attachment of 

 the arms are horse-shoe shaped, moderately large, concave, and have a deep angular 

 notch superiorly. The external surface of all the plates which compose the body are 

 finely corrugated, giving to the species a very neat appearance. 



Column, arms, and abdominal plates unknown. 



Formation and Localities. — It occurs at Burlington, Iowa, in the carboniferous 

 limestone, whence we have been so fortunate as to obtain several specimens. We 

 are not aware of its having been found elsewhere. 



Cyathocrinus cornutus. (New sp.) 



PL 7, fig. 9, a, b. 



Basal plate small, pentagonal, composed of five sub-rhomboid al plates, firmly 

 adhering among themselves ; flattened or slightly concave, with a small 

 pentapetalous central perforation. First series of perisomic plates five, four of which 

 are pentagonal and one hexagonal. Each plate is lengthened into a process 

 approaching to a conical form, which projects downwards and outwards for some 

 distance below the plane of the basal plate ; so that when a side view of the visceral 

 cup is taken, this plate is not visible. The second series consists of six massive 

 plates, of which five support the arms, and rest by their lower salient angles in the 

 reentering angles formed by the union of the first series. The arm-bearing plates 

 are conical in their centres, and present, at their superior edges, a large bevelled 



