• IOWA ACADEMY OF SCIENCES. 109 



be grouped under C. decisum. Say, if that form is a part of the series, or 

 under C. integrum, Say, if the former is distinct. Reversed specimens of 

 0. rufum, subsolidum and obesum have been collected. 



Family Zonitid^. 

 Oenus Zonites. 



The Loess fossil which vpas repoi'ted in the former list under the name Z. 

 limatulus. Ward with the suggestion that it is probably distinct has since 

 been described by Mr. H. A. Pilsbry, under the name Z. shimekii. A large 

 series collected in the La'ss of Iowa and Nebraska shows this to be very con- 

 stant in its characters. 



Fam,ily Helicid.e. 

 Genus Vallonia. 



In the former list two forms were reported: V. jndchella, Muell, and V. 

 ptilrhella costata, Muell. Dr. Victor Sterki, who has recently published an 

 extensive monograph of the genus* recognizes four species among the forms 

 occurring in Iowa. They are: 



V. Pulchella, Muell — The large, smooth (ecostate) form with nucleus 

 smooth. 



V. gracilicosta. Rein hard — Equally large or larger, but with distinct 

 costs? and nucleus spirally marked with faint ribs or Hues. 



Y. parvula, Sterki — Small; ribs prominent; nucleus with fine revolving 

 lines; body-whorl not descending to aperture above. Lip retiexed. 



V. perspectiva, Sterki — Small; ribs prominent; nucleus without lines; 

 body-whorl descending to aperture; lip none, or only slightly expanded. 



Of these V. pulchella is the form formerly recognized by that name, 

 while the last three were collectively included under the var costata, speci- 

 mens of gracilicosta being also mingled with F. pulchella. 



I have specimens of V. imlchella as here restricted from Iowa City and 

 Muscatine. 



V. gracilicosta, Reinhard, was collected by me at Eastport, in Fremont 

 county. 



V. parvula, Sterki, is the form which was most commonly sent out as 

 var. costata. It is very common at Davenport, Muscatine, Iowa City and 

 Eastport. This is clearly a distinct species, not like var. costata, as compar- 

 isons with European specimens of the latter clearly show. It is not at all 

 difiicult to distinguish between this and V. pulchella, and the only wonder 

 is that they were ever united. 



V. perspecliva, Sterki— Four specimens of this species were sent to Dr. 

 Sterki from Eastport. A microscopic examination of a large number of 

 shells shows that the markings of the nucleus and the deflection of the body- 

 whorl are not always satisfactory characters and it may be necessary to con- 

 sider V. j)erspectiva a variety of V. parvula and perhaps V. gracilicosta a 

 variety of V. pulchella, unless other characters than those enumerated 

 should determine otherwise. 



Family Pufid^. 



Of the species heretofore reported, the following have been found at 

 Eastport, Fremont county: Pupa armifera. contracta, jientodon, fallox and 

 milium, and Vertigo ovata. Vertigo milium should have been Pu2)a milium 



♦Observations on "Vallonia, by Dr. V. Sterki.— Proc. A. Nat. Sc. Phil, May 30. 189.3. 



