1889.] NATURAL SCIENCES OF PHILADELPHIA. 295 



closely incurved but not contiguous. "When partially embedded in 

 the matrix the apical portions are usually not visible, thus giving it 

 the appearance of the obliquely conical forms, whereas it actually 

 belongs to the typical section of the genus. In the type the longitu- 

 dinal plications are much more prominent than in a representative 

 .specimen of the species, while in some forms the longitudinal folds 

 are nearly obsolete. Immature shells are laterally compressed and 

 the surface is perfectly glabrate, with no indications whatever, of . 

 plications or imbricating lines of growth. As the individuals 

 became larger the aperture becomes relatively more expanded and 

 assumes a subcircular outline. 



Straparollus macromphalus Winchell. 



Straparollus maeromphalas "Winchell, 1863. Proc. Acad. Nat. 

 Sci. Phila., p. 20. 



Shell of medium size, composed of about four regularly rounded 

 volutions ; spire somewhat elevated ; suture moderately impressed ; 

 umbilical cavity rather deep ; aperture circular. 



The spire in this species is more elevated than in any other con- 

 generic form from the vicinity of Burlington, except, perhaps, S. 

 barrisi "Win., with which, if recent determinations are correct, it may 

 prove synonymous. It has close affinities to Straparollus (Euom- 

 phalus) cyclostomut (Hall), from the Iowa Devonic rocks at Iowa 

 City. Among foreign species it bears a striking resemblance to S. 

 eostellatus Sowerby? The form under consideration appears to be the 

 most common species of the genus found in the locality, coming 

 from the upper calcareous layers of the Kinderhook. 



Straparollus barrisi Winchell. 



Straparollus barrisi "Winchell, 1863. Proc. Acad. Nat. Sci. Phila., 

 p. 20. 



This species is closely related to S. maeromphalas "Winchell. It 

 appears to differ in having three barely perceptible angularities on 

 the body whorl, and the spire slightly more depressed. It is from the 

 arenaceous layers of the Kinderhook. 



Straparollus (Euomphalus) amnion. (White ami "Whitfield), de- 

 scribed from the Kinderhook beds of the same locality, has not 

 been noted recently. It is a small form and said to have its closest 

 affinities with S. (Euomphalus) spergenensis (Hall) from the "War- 

 saw. 



