No. 4. — A Fourth Supplement to the Fifth Volume of the Terres- 

 trial Air-Breathing Mollusks of the United States and Adjacent 

 Territories. By W. G. Binney.^ 



The following pages are believed to contaiu^ all that has been added 

 to our knowledge of the subject prior to date. 



Students are requested to note that in the Third Supplement, p. 214, 

 the figures of Arionta Diabloensis and Bridgesi are reversed. On p. 225, 

 Explanation of Plate VII., the references E and F are reversed : on 

 p. 226, Explanation of Plate XL, Figures D and G are reversed. 



Burlington, New Jersey, July 1, 1891. 



Glandina decussata, Desh. 



Plate I. Fig 4. 



Under the name of decussata, specimens are found in most collections which 

 can hardly be referred to that species. I have figured one of them, and its 

 dentition has already been described and figured in my Third Supplement. 

 The shell is readily recognized hy its more cylindrical form. Should it prove 

 distinct from decussata, I would suggest for it the specific name of Singleyana. 

 I received it from Bexar County, Texas, collected by Mr. Wetherby. 



Selenites Vanoouverensis, Lea, var Keepi, Hemphill. 



Plate II. Fig. 5. 



Shell umbilicated, greatly depressed, thin, smootli, shining, trRnsparent, scarcely 

 marked by the delicate wrinkles; very light horn-color; whorls over four, some- 

 what flattened above and beneath, and scarcely descending at the aperture, spire 



1 The Terrestrial Air-Breathing Mollusks of the United States and the Adjacent 

 Territories of North America, described and illustrated by Amos Binney. Edited 

 by A. A. Gould. Boston, Little and Brown, Vols. L, XL, 1851 ; Vol. IIL, 1857. 

 Vol IV., by W. G. Binney, New York, B. Westermann, 1859 (from Boston Journ. 

 Nat. Hist). Vol. V., forming Bull Mus. Comp. Zo51., Vol. IV., 1878. Supplement 

 to same, in same. Vol. IX. No. 8. 1883. Second Supplement, in same, Vol. XIII. 

 No. 2, 1886. Third Supplement, in same, Vol. XIX. No. 4, May, 1890. 



VOL. XXIL — NO. 4. 



