In tlie monumental 'Jagne r Institute Papers, Dr. Dall fl) des- 

 cribed manj? nev; species and noted the occurrence of previous- 

 ly" described forms; tlie last fascicle also include" ^ '-rief 

 discussion of the fa^ma and a check-list (2). 



(1). Dall, v;. I-I,, Trans. '.Tagner ?ree liTst^ 3ci . , Philadelphia, 

 vol. 5, pts. 1-6, 1890-1903. 



(£). Idem, -':. u, pp. 1580-15 ?T, 190S. 



The i^terial for thie present study has been furnish- 

 e'l by two collect ons that are the property of the Johns "-^^op- 

 kins Universitj/; the one is the result of several accessions to 

 the valuable assemblage of Tertiary rao": luscs nade by Mr. T. H. 

 Aldrich, of Birmingham Alabama, the other a collection obtained 

 by -Dr. James E.'Duerden, now of P.hodes University College, 

 Grahamstov/n, -^outh Africa, in' 1899, ',7hile he vras Curator of the 

 Musexan of Kingston, Jamaica. Tlirough the kiiidness of the Mus- 

 eum authorities the writer lias also h. ^ess to the coll- 

 ections housed at the rational llusemn. 



