8i6 



NORTH AMERICAN INDEX FOSSILS. 



671. P. copei White. (Fig. 1205, b, c.) Cretacic. 

 Large, elongate ; spire small ; body whorl relatively slender. 

 Upper Cretacic (Judith River beds) of Upper Missouri River 



region of Montana, and the Bow and Belly River regions of 

 Canada. 



672. P. felix White. Cretacic. 



Large ; body whorl strongly shouldered ; 

 sides straight and vertical; growth lamellae 

 often with serrate edges. 



Laramie of Colorado. 



673. P. bridgerensis Meek. (Fig. 1205, e.) 



Eocenic. 



Smaller than preceding, with higher spire 

 and less rounded whorls. 



Bridger beds of southern Wyoming. 



674. P. pleromatis White. (Fig. 1205, d.) 



Eocenic. 



Shorter and stouter than P. copei, with 

 aperture wider and shorter. 



Wahsatch group of southern Wyoming, 

 Colorado and Utah. 

 675. P. meigsii Dall. (Fig. 1204.) Pliocenic. 



Spire higher and of more volutions than in P. copei; lip much 

 prolonged anteriorly. 



Caloosahatchie marls of Florida. 



Fig. 1204. Physa 

 meigsii, X I - 2 - (After 

 Dall. ) 



Family Limn^eidjE Brod. 

 CCXII. Limn^ea Lamarck. 

 Shell very thin, translucent, with small acute spire and large 

 body whorl ; aperture wide, with sharp outer lip. Jurassic-Recent ; 

 (fresh- water). 



676. L. altivuncula White. (Fig. 1203,/, g.) Jurassic. 

 Small, slender, embracing part way to middle only; aperture 



somewhat drawn out anteriorly. 



Morrison formation near Canyon City, Colorado. 



677. L. consortis White. (Fig. 1203, h.) Jurassic. 

 Somewhat larger than preceding ; whorls ventricose ; spire short ; 



suture deep; nearly rectangular depression between the whorls. 

 With the preceding. 



