6?. NEW YORK STATE MUSEUM 



striatus Agassiz, from the British Lower Carbonic limestone.' The 

 present example differs from the latter species, however, in the lesser com- 

 pression of the crown, fewer lateral cones, and peculiar arrangement of the 

 coronal striae. As many as 35 fine parallel nonbifurcating striae are visible 

 on the external face of the principal cone, those of the middle portion run- 

 ning vertically, and those along the sides curving gradually outwards and 

 terminating in a faint ridge along the lateral margin. The apexes of the 

 median and nearly all of the lateral cones have unfortunately been broken 

 away in the type specimen, and the root, also, is wanting. The width 

 across the base line, in its present condition, is 3.6 cm. 



The unique specimen answering to the above description forms part 

 of the collection purchased from the late Professor James Hall by the 

 American Museum of Natural History in New York, and bears the inuseum 

 catalogue number of 4257. It is labeled as having been derived from the 

 " Corniferous" (Columbus) limestone in the vicinity of Columbus, O., and 

 the characteristic appearance of the matrix leaves no doubt as to the 

 authenticity of the record. Its geological antiquity is greater than that 

 of any other known species. 



Formation and locality. Columbus limestone (Ulsterian) ; Columbus, O. 



Cladodus monroei Eastman 



Plate I, figure 5 



1900 Cladodus monroei C. J?. Eastman. Jour. Geol. 8: 36, text fig. 2 

 The type of this species is a small, imperfectly preserved tooth found 

 by Mr Charles E. Monroe in the Hamilton limestone of Milwaukee, Wis. 

 The median cone is robust, very thick at the base, and indistinctly striated. 

 The external denticles are also stout in proportion to the size of the pnn- 

 cipal cone, but the three intermediate denticles of either side are excessively 

 small. The total hight of the median cone probably amounted to less than 

 1.5 cm, and the width across the base 2.5 cm. 



Formation and locality. Hamilton limestone (Erian) ; Milwaukee, Wis. 



' The teeth recently described under this name by E. B. Branson from the Salem lime- 

 stone of Indiana are clearly distinct, and require a new specific name. 



