Contributions to Palaeontology. 35 



Group. In a paper published in 1806, and now forming part of the 

 Twent^'-Fourth Annual Report on the New York State Museum of 

 Natural History, Prof. James Hall named the species described b}' 

 him in Foster & Whitney's Report, C. anteceptus, and described and 

 figured C. Salferi, having 2G marginal plates. These four species are 

 all that have been describ d heretofore. 



We have described one species, C. parvus, having the same number 

 of marginal plates possessed by C. sulteri^ but the species must be 

 widely ditfereut from each other. C. salteri is much the largest, and 

 had two rows of plates on the out side of the inner rim, which were 

 surrounded by a granulose border, and is otherwise quite distinct 

 from C. parvus, 



From all the specimens, which we have examined, we are led to infer, 

 that in each of the species, which we have described above, the sub- 

 marginal rim was perforated by a tubular canal, and was grooved upon 

 the outside and upon the inside; that from a central or subcentral 

 point, some kind of a radiated structure, extended into the groove on 

 the inside of the submarginal rim, and was connected by pores to the 

 marginal riiii; the marginal rim consists of the same number of plates 

 as the submarginal, which were inserted into the groove and possessed 

 little channels connected with the pores that penetrated within. We 

 are not sure, however, that we are able to throw any light upon the 

 fossil, beyond the descriptions and illustrations furnished above, and 

 we have taken the occasion to refer to the literature upon the subject, 

 because we have been unable to find indicated-in our specimens either 

 the structure pointed out by Billings and Salter or b}' Prof. Hall. 



Cod ASTER PULCHELLUS, u. sp. (Plate II., fig. 13, natural size; 13«. 

 magnified view of the summit). 



[Eiy—Pulchellui^, beautiful, little ] 



This species is small, smooth, and obpja-amidal. The point of at- 

 tachment to the column is very small. There are three basal pieces, 

 each one of which is elevated in the middle, and depressed on the uni- 

 ting sides; this makes the base somewhat triangular. One of the 

 basal plates is pentagonal, and the other two are hexagonal. The 

 pentagonal plate has two upper sloping sides. The hexagonal plates 

 have three upper sides, the middle ones being a little concave, and 

 each supporting a radial plate, while the other three radials are sup- 

 ported between the upper sloping sides of the basal plates. 



There are five radial plates, each one of which is sharpl}^ angular in 

 the middle. This gives the fossil, above the basal plates, a marked 

 pentagonal form. Two of the radials are pentagonal, the others are 

 hexaaonal. 



