84 Cinciniiali Sociely of Natural History. 



in which these fossils occur, having such thin plates as the 

 segments of these bodies represent. 



4. The outer papillae bearing covering of crinoids is the 

 first to suffer destruction, and it is rare, in pakeozoic rocks, to 

 see this part represented in any state of preservation. 



We have no evidence to offer to show that they represent 

 the tubes of Annelida, but probably they do, and as we can 

 not class them anywhere else, we leave them where others 

 have placed them. 



Found by Mr. Kaber in rocks of the age of the Utica Slate, 

 near low water mark, below Mowry's Foundry, in Cincinnati, 

 and now in his collection. 



Cyclocvstoidks cincinn.\tikn.sis, n. sp. 

 Plate /, Fio-. 7, natural size : Fig. <S\ niaguijicd t'U'o dianutcrs. 



This species, so far as known, consists of a ring composed 

 of thirty equal subcuneate plates, surrounded with a thin 

 rim composed of minute granular plates. The plates of the 

 ring are narrow and separated by rather wide furrows, the 

 sharper edge being on the inner side of the ring ; they show 

 no surface ornamentation. The groove on the inner side of 

 the ring can be seen distinctly, but the rest of the internal 

 part is unknown. The outer rim is composed of such minute 

 plates, that they can hardly be distinguished with an ordinary 

 magnifier. The diameter of the specimen illustrated is al)out 

 one-third of an inch, but the width of the rim is only about 

 two-hundredths of an inch. 



This species is distinguished from such species as C. vmgnus 

 and C. hellulns, by the character and structure of the outer 

 rim alone, and it will be distinguished from most other species 

 by the shape of the plates in the ring, and, as we think the 

 number of plates in the ring is of sjiecific importance (and it 

 is, so far as any learning and research has 3'et extended), that 

 character will distinguish it from all heretofore described, as 

 none have been defined having thirty plates. There is no 

 described species with which it is necessary to make a com- 

 pari.son, for the purpose of distinguishing it. 



Found in the Hudson River Croup, near the top of the hills, 

 in Cincinnati, and now in the collection of Mr. Faber. 



