100 THE NAUTILUS. 



available for the work in progress, and the members of the Section 

 will be very grateful for any assistance they may receive from their 

 brethren of other States. 



In behalf of the Section of Conchology, I would therefore earn- 

 estly request that all collectors, who have any Michigan shells in 

 their collections, would furnish a list of the species and localities, 

 which may be filed for permanent record. Blanks will be gladly 

 furnished for that purpose to any one who will address the writer 

 at 18 Moffat Building, Detroit, Michigan. 



ON A NEW SPECIES OF VITREA FROM MARYLAND. 



BY WM. H. BALL. 



The land shell fauna of the north-eastern U. S. has been so- 

 thoroughly searched, and by so many collectors, that we do not ex- 

 pect the addition to it of good and valid new species, unless among 

 the minuter forms like Vallonia. However, as if to prove that 

 hope may spring eternal in the conchological breast, a new species 

 with undoubtedly distinct characteristics has come to hand from 

 Maryland. 



Vitrea Raderi n. sp. 



Shell depressed, four-whorled, smooth except for faint rather reg- 

 ularly spaced incremental lines above, of a pale waxen whitish 

 color ; spire hardly raised above the last whorl, which is much the 

 largest; periphery evenly rounded, suture appressed, base moder- 

 ately rounded, the umbilical slope of the last whorl somewhat flat- 

 tish ; umbilicus very wide, exhibiting all the volutions; aperture 

 wider than high, the upper margin slightly in advance of the lower 

 lip, the two connected by a thin wash of callus over the body. Alt. 

 1'5, max. diam. 41), min. diam. 3'0 mm. 



Received from Prof. Howard Shriver, as collected at Cumber- 

 land, Md., in the summer of 1897 ; a single specimen. 



The nearest relative of this species is Zonites wheatleyi Bland, 

 which is a larger shell with higher spire, more rounded whorls and 

 a much smaller and more steep sided umbilicus. It may be men- 

 tioned that the figure of Vitrea wheatleyi in Binney, Bull. 28, U. S. 

 Nat. Mus., is inaccurate in representing the umbilicus as wider than 

 it really is in that species. The large form of Z. wheatleyi referred 



