128 NON-MA 1UNE FOSSIL MOLLUSCA. 



PLATE 24. LARAMIE. 



Viviparus RETUSUS Meek &, Hayden. Page 61.) 



Fig. 1. Lateral view of au adult example. 

 Fig. 2. Similar view of another example. 

 Fig. 3. Lateral view of another example, showing' aperture. 

 (All natural size.) 



Viviparus oonradi M. & H. (Page 61.) 



Fig. 4. Lateral view of an adult example. 



Fig. " 5. Opposite view of the same. 



Fig. ti. Another example, more than, usually elongate. 



Viviparus leidyi M. & H. (Page 61.) 



Fig. 7. Lateral view of the type specimen. After Meek. 



Viviparus leidyi var. formosus M. & H. (Page 61.) 



Fig. 8. Lateral view of the type specimen. 



Fig. 9. Opposite view of the same. After Meek. 



Viviparus trochiformis M. <fc H. (Page 61.) 



Figs. 10, 11,12, 13, 14, 15, and 16. Lateral views of different examples; nil natural size. 



Tulotoma TnoMPSONl White. (Page 61.) 



Figs. 17, 18, 19, 20, and 21. Lateral views of different examples, showing the ornamen- 

 tation of the first to be nearly like that of V. irodriformix, and the increas- 

 ing size of the nodes towards the higher numbers; all of natural size, and 

 all from Northern Colorado, east of the Rocky Mountains. 



Fig. 22. Lateral view of an example from Southern Wyoming, west of the Rocky 

 Mountains. 



Viviparus peculiaris M. & H. (Page 61.) 



Fig. 23. Lateral view of the type specimen of Meek & Hayden. 

 Fig. 24. Opposite view of the same, natural size. 



Viviparus plicapressus W. (Page 61.) 



Fig. 25. Lateral view, natural size. 



Fig. 26. Similar view of another example. 



ACROLOXUS MINUTUS M. & H. 



Fig. 27. Apical view, magnified to four diameters. 



