wHiTEAvEs] LARAJHE AXD CRETACEOUS INVERTEBRATA. 39 



LUCIXA OCCIDEXTALIS, Xorton. 



Tellina occidentaUs, Morton. 1S42. Jour. Ac. Xat. Sc, Phil., vol. Till, p. 210, 



pi. 11, fig. 3. 

 Mould of LiKina^ Owen. 18.52- Rep. Geol. Surv. Wise, Iowa and jMinn., pi. 7, 



fig. S. 

 Lwina occide.ntali.i ' Meek and Hayden. 18.56. Proc. Ac. Xat. Sc, Phil., vol. 



^^II, p. 272. Xot Lvcina occidmtali.i, Eeeve, 1850. 

 " " Meek (as of Morton). 1876. Eep. U.S. Geol. Sur^-. Terr., vol. 



IX, p. 134, pi. 17, figs. 4, a, b, c, d. 



Bull Pound Creek, Section 3, Township 26, Eange 14, west of 4tli 

 Principal ileridian, J. B. Tyrrell, 1884 : ten specimens, with both 

 valves and the test preserved. Old Wives' Creek, ToAvnship 10, Piange 

 11, we>.l of 4th Principal Meridian, E. G. McConnell, 1884: two small 

 specimens which belong to the form to which Hall and Meek gave the 

 name Ij. subundata. 



The largest individuals from Bull Pound Creek are exactly like Meek's 

 representations of Lucina occidentalis on plate 17, figures 4 a and 4 b, of 

 the ninth volume of the United States Geological Survey of the Terri- 

 tories, but the smaller ones correspond quite as closely to his figures of 

 L. subundata on the same plate. The few Lucinse which have yet been 

 collected from the Fort Pierre Group of the Canadian ISTorth-West, 

 however, all clearly belong to a single species, and it is extremely 

 probable that L. suhundata is only the young of L. occidentalis, as Mi-. 

 Meek has suggested may be the case. In reference to these two 

 nominal species and to the variety ventricosa, Mr. Meek remarks (on 

 page 136 of the volume last cited), " it may be possible that all 

 three of the types here described are merely varieties or represent 

 different ages of the same species. Indeed, I confess that I am not 

 altogether satisfied with the conclusion that thej' belong to more than 

 one species ; but having already separated them, it is perhaps better 

 to continue this arrangement than to unite the whole under one name 

 doubtfully.'' 



Tancredia Americana, Meek and Hayden. 



Eeltarujia Americana, Meek and Hayden. 1856. Proc. Ac. Nat. Sc, Phil., vol. 



VIII., p. 274, and (1860) lb., vol XII., p. 185. 

 Tancredia Americana, Meek. 1876. Rep. U.S. Geol. Surv. Terr., vol. IX., p. 142 



pi. 38, figs. 1, a, b, c, d, e, f, g, h. 



Berry Creek, Section 31, Township 25, Eange 12, west of 4th Prin- 

 cipal Meridian, J. B. Tyn-ell, 1884: one adult specimen with the valves 

 spread out on a piece of sandstone. 



