22 



central dorsal band, on the last volution, with a furrow on each 

 side bordered by a sharply angular longitudinal line. The shell 

 of this part of the last whorl is not preserved on any of our 

 specimens. The shell is ornamented with numerous longitudinal, 

 revolving furrows separated by fine angular stria). These revolv- 

 ing furrows are visible upon many of the fragments of the casts, 

 but much more strongly marked upon the fragments of the shell, 

 wherever it is preserved. 



This species is readily distinguished from B. blairi by the re- 

 volving furrows, and from all other described species by the 

 general foim and surface ornamentation. Species of Belleroplwn 

 have been described from the upper Taconic system and from 

 nearly every recognized group of rocks up to the Upper Coal 

 Measures. About ninety species have been illustrated and those 

 which have been named and not illustrated might as well be 

 struck out of the list, for they cannot be recognized by the 

 definitions alone. There is such a general resemblance in the 

 fossils belonging to this genus, that a common observer having 

 learned one species can tell a Belleroplwn wherever he sees it. 



Found by R. A. Blair, in the Chouteau limestone, near Sedalia, 

 Missouri, and now in the collection of S. A. Miller. 



CLASS PTERPODA. CLASS GASTROPODA. 



ORDER CONULARIDA, n. ord. 



This name is proposed to receive conical and pyramidal, pelagic 

 shells, which may or may not have been contracted toward the 

 mouth, but the texture of which is always horny with lime 

 phosphate. The shells during the lives of the animals were 

 llexible. They are smooth, or longitudinally divided and trans- 

 versely furrowed. There are no muscular scars on the casts or 

 on the shells. All belong to the paheozoic rocks. We refer to 

 this order the family Conulariidce, and the family Enchosiomidce 

 hereinafter described. 



Waagen used the word Conularida in Palaeootologica Indica, 

 page 175, without defining it, or in any way limiting it, except to 

 say, "they were certainly not pelagic shells," and to include in the 

 order three families, which are widely distinct from each other, 

 viz.: Conulariichr, Thecidrr and TentaculUidoe. He did not re- 

 describe the family Conulariidcr, or describe any species belong- 

 ing to it or in any way attempt to throw any light upon it. 

 He had before him shells belonging to the family 

 Hyolithid(v or Thecidrr, and they were the shells for which he 



