REPORT ON PAL^EONTOLOGICAL COLLECTIONS. ; 



concentric stria 1 are usually well defined and very regular, so as to form with 

 radiating stria n line cancellated style of ornamentation. Only concentric mnrki 



This shell is very closely related to the Jurassic species (\ Ims {= IWtm Irn 

 Sowerby), having- much the same form, and almost exactly the same style of ornana 



videst part of the 

 aid obliquely trn 



Locality and position.— -Same as last. 



GASTEROPODA. 



Genus DENTALIUM, Linn. 



Dentajlium 1 subquadratum, Meek. 



Plate 3, fig. l,a,b, c. 

 Pen tali urn ? subquadratum, Meek (July, I860). Proceed. Acad. Nat. Sci. Philad., XII, i 



Shell small, slender, regularly and slightly arcuate, ver 

 tened or a little concave on four sides so as to present a sul 

 angles being a little rounded ; section of internal cavity cir 

 without longitudinal stria or marks of growth. 



Length, about 1 inch; diameter at larger end, 0.05 incl 

 extremity, 0.02. 





in the identii 



should not be ov 





looked by the Paleontologist, m consequence o 

 suspect that it will form the tvpe ot a distinct genus. - ^ 



Locality and ^,7«>«.-Ju.-assie beds on the North Platte, at Red Buttes, lati- 

 tude, 42° 50' north, longitude, 106° 40' west. 



