150 



this is the more remjarkablo, as the waters of the Red river of the 

 north are embraced in a difterent system of drainage, flowing as they 

 do into Hudson's bay at about 52° north latitude. Here is seen an 

 immense area of country producing in its waters nearly the same life 

 as regards the molluscs, a fact highly interesting to the zoologist." 



To Mr, W. G. Binney were transmitted the land shells, which were 

 examined by him Avith great care. I quote the following remarks 

 from his letter: "These shells are all of value, as they form the first 

 contribution to our knowledge of the species found in those regions. 

 They are, however, for the most part alluvial. Succinea Haydeni is the 

 only perfectly fresh species, the animal being preserved in alcohol." 



' ' Helix costata was found in myriads, probably the contribution of 

 many small streams above. Of the previously known species it is the 

 most interesting, having been noticed previously in few localities and 

 small numbers. If any argument were needed to establish the point 

 of H. mhmta (Say) being identical with the European H. j^^dchella 

 (Mull.) it might be found in the fact of the ribbed variety being also 

 found in this country." 



The following catalogue comprises all the freshwater and land 

 shells known to us on the upper Missouri: 



FLUVIATILE SHELLS. 



1. Unio alatiis, Say. Big Sioux river. 



2. Unio levississiinvs^ Lea. Big Sioux river. 



3. Unio lutcolus^ Lam. " " 



4. Unio asperimus, liC'cX. " " 



5. Unio rectus, Lea. " " 



6. Unio elegcms, Lea. James river. 



7. Unio zizzag, Lea. White Earth river. 

 8^ Unio miadontoides, Lea. James river. 



9. Magaritana complanata., Lea. Fort Clark, in Missouri. * 



10. Anadonta Fermsaciana, Lea. White river, Nebraska. 



IL Jjymncct elodes, Say. Mouth Big Sioux river. 



12. Lymnea nuttaUiana, Lea. " " 



13. Lynmea humilis, Say. " " 



14. Lymnea Haydeni, hea.. " " 



15. Lymnea Kirtknidiana, Lea. " " 



16. Lymnea umhrosa, Say. Grindstone creek, Nebraska Territory. 



17. Lynmea I uhricoides, Lea. " " 



18. Lymnea FJiiladeljjMca, Lgh '' " 



19. Planorhis bicarinatus, Say. Mouth Big Sioux river. 



20. Planorhis trivolvis. Say. " ' ' 



21. Planorhis lent us, Say. " " 



22. Planorhis iMrv us. Say. " " 



23. Planorhis campanulatus, Say. " " 



24. Physa heterostroj)ha. " " 

 2b. Physa Integra? R'SlU. " 



26. Physa elongata. Say. " " 



27. Physa ampularia, Say. " " 



