118 — Bulletin American Museum of Natural History. [Vol. XXXIV, 
weak oblique strize marking the lines of growth; apex quite smooth, without riblets; 
lip thin, but columella rather stout; 
no umbilicus. 
Variety a. Spire depressed. 
Variety b. Spire elevated, conoidal. 
os ~S Sand Coulee Beds (Eocene); five 
Fig. 3. Helix veterna veternior n. subsp. miles 8S. E. of mouth of Pat O’Hara 
Showing variation; the middle oneis thetype. Creek, Clark’s Fork Basin, Wyoming; 
| 1912 (Granger and Stein). 
In its typical form, of which two specimens are before me, apparently 
more or less immature, this looks like a distinct species. Variety b, how- 
ever, is much like H. veterna. There is a series of species, consisting of 
veterna Meek & Hayden, from the Wind River Eocene, riparza White, from 
the Green River Eocene, and leidyi Hall and Meek, from the Oligocene, 
which are so closely related that from the shells alone they are scarcely 
separable. I examined the types of these in the U. 8. National Museum, 
and made the following notes: 
Helix leidyi Hall & Meek. 
2012 (Types). White R., Nebraska. Agree with those discussed and 
figured in Bull. Amer. Mus. Nat. Hist., xxxi, p. 232, pl. xxii. 
13303. Determined as lecdyz by Marcou. Salt Lake City, Utah. Seems 
correct. 
Helix veterna Meek & Hayden. 
1975 (Types). Wind River Valley. I could not distinguish this from 
leidyr. Both species show the same variation in the height of the spire as 
was noted in the Amer. Mus. N. H. series of leidyi, but each presents all 
necessary intermediate forms, and the difference is partly due to compres- 
sion, though not wholly so by any means. | 
Helix riparia White. 
8881 (Type). Eight miles below Green River City, Wyoming. In- 
ternal cast, with fragments of outside, indicating rather coarse flattened ribs. 
Looks like a young veterna-leidyi, of the form with higher spire; perhaps 
differs by less elongated aperture, and outline of upper side of last whorl in 
front view seems more oblique than in veterna. On the whole, this appeared 
not to be a distinct species. 
We thus have a general type extending from the Sand Coulee Beds 
