Pyrgulopsis Scalariformis. 173 



body-whorl is somewhat detached at its termination, thus 

 answering to Wolf's description. 



The statement that "the outlines of the apical whorls are 

 wholly unlike the figured type of Wolf's species" is only 

 partly true. While the latter does not accurately represent 

 the apex it is not "wholly unlike" that of the strongly carinate 

 form. The apparent difference is due to the inaccuracy of 

 the drawing rather than to any difference in the specimens. 



In Wolf's description as quoted above, the length is given 

 as one-half inch. This is evidently a mistake as Mr. Wolf 

 informs the Vv'riter that his specimens average one-eighth of an 

 inch, thus agreeing with the dimensions represented on the 

 plate with the figure of the type. 



These facts collectively convinced the writer that P. scalari- 

 formis and P. rnississippiensis are the same. In this opinion 

 he was confirmed by the receipt of a small lot of shells from 

 the original set which ^Mr. Wolf kindly forwarded. These 

 leave no longer any doubt concerning the identity of the two 

 "species." 



If then we adopt the new genus Pyrgulopsis the name will 

 stand: Pyrgulopsis scalariformis^ (Wolf) Call and Pilsbry. 



The section represented in Fig. 2 is of much interest from 

 a geological standpoint. 



As already noted in the preceding, the lov/ermost stratum, c, 

 is composed of sand and gravel, the finer sand being mingled 

 with great numbers of shells which belong almost exclusively 

 to fluviatiie gent^ra. This was evidently an old sand-bar upon 

 which were heaped the thousands of shells v/hile it still lay in 

 the path of a strong current, — a fact indicated by the coarse 

 material as well as by the shells. These shells were carried 

 but a short distance from their muddy habitats, and are in a 

 fair state of preservation. 



The middle stratum, 5, was probably deposited while the 

 strong currents of flood-times alternated with the more slug- 



