GEOLOGICAL SURVEY OF THE TEERITORIES. 517 



but not very veutricose; suture well defined; aperture uarrow-subovate, 

 arcuate, acutely angular above, and about twice as long as tbe spire ; 

 columella twisted into a rather prominent fold. Surface with fine sharp 

 lines of growth. 



Length about 1.15 inches; breadth, O.GG inch. 



This is a fine large species, with a more prominent spire than any of 

 our recent species resembling it in other respects. None of the speci- 

 mens found are perfectly preserved. 



Locality and position. — Church Buttes, fourteen miles from Fort 

 Bridger, Wyoming Territory. Tertiary. 



LiMNiEA, LlMNOPHYSA (?) COMPACTILIS, Meek. 



Shell rather small, slender, subfusiform; spire conical, a little longer 

 than the aperture; volutions about six, very little convex, and (for a 

 Limnsea) compactly wound together; last one not ventricose, but rather 

 produced below; suture distinct though shallow, and but little oblique; 

 aperture narrow subovate, very narrowly rounded below, and acutely 

 angular above; outer lip not dilated: columella a little twisted, and 

 apparently so as to form a small oblique plication. Surface smooth. 



Length of a medium-size specimen, 0.50 inch, breadth 0.20 inch ; length 

 of aperture 0.22 inch; breadth of aperture 0.10 inch. 



I have not seen specimens of this little shell showing the columella 

 clearly enough to be sure that it belongs to the genus Limna'a. There 

 is a compactuess in the rolling together of the volutions of the spire, 

 and a want of obliquity and deepness, observable in the suture, that 

 are not often seen in that genus, and remind one of some forms referred 

 to sections of the old genus Bulimus, such, for instance, as B. {Thau- 

 mastus) calif ornicus. 



Locality and position. — Upper beds of the series exposed at Separation, 

 on the Union Pacific Eailroad, apparently belonging to the Tertiary. 



Pupa? Leidyi, Meek. 



Shell clavate-subcylindrical, being about three times as long as wide, 

 a little wider above the middle than below, and very obtuse- at the 

 apex; volutions about fifteen, very compactly coiled together, and ex- 

 tremely narrow in their vertical diameter; suture merely linear, and so 

 slightly oblique as to appear to the eye almost at right angles to the 

 longer axis of the shell; aperture unknown, but apparently small. Sur- 

 face ornamented by small, comparatively distinct, regular, crowded, 

 oblique stri£e of growth. 



Length about 0.55 inch ; greatest breadth, 0.20 inch. 



The volutions of this shell are so compactly coiled, so very narrow, 

 and show so little obliquity, as to give it the appearance of the abdo- 

 men of some insects, the volutions looking like rings, and the obtuse 

 apex of the spire like the posterior extremity-of an insect abdomen. I 

 have seen but two specimens, and neither of these shows the aperture; 

 consequently it is not possible to determine whether or not it is a true 

 Pupa. Indeed its subcylindrical form, and nunun^ous volutions, give it 

 much the appearance of Eolospira of Alliers, and it is quite probable 

 that when specimens showing its aperture can be examined the name 

 may have to be changed to Holospira Leidyi. Specifically it rather 

 closely resembles H. Ecmondi, an existing species found at Souora, 

 Mexico. It has a more obtuse apex, however, than that s])ecies, and 

 also differs in having more narrow and compactly coiled volutions, and 

 a less oblique suture. 



