304 BULLETIN 53, UNITED STATES NATIONAL MUSEUM. 



249. Helcion sexsulcatus Meek and Hayden. Holotype. 



Montana (Cret.). Yellowstone River, near Miles City, 

 Montana. 

 Meek and Hayden, Proc. Acad. Nat. Sci. Phila., VIII, 1856, p. 68. 

 = Anisontyon sexsulcatus. 



244. Helcion subovatus Meek and Hayden. Holotype. 



Montana (Cret.). Yellowstone River, Montana. 



Meek and Hayden, Proc. Acad. Nat. Sci. Phila., VIII, 1856, p. 68. 



= Anisomyon subovatus. 



45827. Helcionopsis striata Ulrich. Holotype. 



Richmond (Ord.). Marion County, Kentucky. 



Ulrich, Geol. and Nat. Hist. Surv. Minn., Final Rept., Ill, Pt. II, 

 1S97, p. 827, pi. 61, figs. 29, 30. 



45828. Helcionopsis subcarinata Ulrich and Scofield. Cotypes. 



Trenton (Ord.). Goodhue County, Minnesota. 



Ulrich and Scofield, Geol. and Nat. Hist. Surv. Minn., Final 

 Rept., Ill, Pt. II, 1897, p. 827, pi. 61, fig. 28. 



18324. Helenia bella Walcott. Cotype. 



Lower Cambrian. Conception Bay, Newfoundland. 



Walcott, Proc. U. S. Nat. Mus., XII, 1889, p. 39; Tenth Ann. Rept. 

 U. S. Geol. Surv., 1890, p. 616, pi. 78, figs. 4-40. 



1 1 1939. Helicina ballista Dall. Cotypes. 



111941. Oligocene. Ballast Point, Tampa, Florida. 



Dall, Trans. Wagner Free Inst. Sci. Phila., Ill, Pt. I, 1890, p. 3, 

 pi. 1, figs. 2, 2a. 



1 1 1943. Helicina ballista tampae Dall. Cotypes. 



Oligocene. Ballast Point, Tampa, Florida. 



Dall, Trans. Wagner Free Inst. Sci. Phila., Ill, Pt. I, 1890, p. 4. 



474. Helicoceras angulatum Meek and Hayden. Holotype. 



Fort Pierre (Cret.). Head of south branch of Cheyenne 

 River, South Dakota. 



Meek and Hayden, Proc. Acad. Nat. Sci. Phila., for i860, p. 176. 



= Heteroceras ? angulatum. 



22934. Helicoceras ? corrugatum Stanton. Holotype. 



Colorado (Cret. ). Turkey Creek, Huerfano Park, Colorado. 



Stanton, Bull. No. 106, U. S. Geol. Surv., 1893, p. 165, pi. 35, fig. 5. 



473. Helicoceras mortoni tenuicostatum Meek. Cotypes. 



Fort Pierre (Cret.). Great Bend of the Missouri, below 

 Fort Pierre, South Dakota. 



Meek, Rept. U. S. Geol. Sun-. Terr., IX, 1876, p. 487, pi. 22, figs. 

 3a-c. 



See Helicoceras tenuicostatus. 



